fix(mentor): defer in-app-notification emails when mentoring round is draft

Mentor-assignment flows (mentor.assign, autoAssign, bulkAssign,
bulkAutoAssign, autoAssignBulkForRound) call createNotification and
notifyProjectTeam for MENTEE_ASSIGNED / MENTOR_ASSIGNED. Both
notification types have NotificationEmailSetting.sendEmail = true, so
the notification system fires its own styled email in addition to the
explicit mentor-team / coalesced emails on the same code path. The
earlier defer-emails-until-round-open fix only gated the explicit
sendMentorBulkAssignmentEmail / sendMentorTeamAssignmentEmail calls;
this parallel email path kept firing immediately at every assignment.

Result on prod 2026-05-26: Camille Lopez (assigned to 9 projects via
two bulk_assigns) received 7 emails at 15:04 + 1 at 15:32 from the
notification-system path during draft, plus 1 coalesced email at the
18:20 round activation = 9 sends instead of 1. Every PEARL team
member (and equivalents on other teams) received 3 emails for the
same reason.

Fix
- Add `skipEmail?: boolean` to CreateNotificationParams,
  createNotification, createBulkNotifications, and (via spread)
  notifyProjectTeam. When true the in-app notification row still
  fires but the parallel email send is suppressed; the coalesced
  mentor email and team intro at activateRound time remain the
  single source of email truth.
- Wire it up in every mentor-assignment site: compute the existing
  shouldDeferEmailsForProject gate once before the createNotification
  / notifyProjectTeam calls and pass `skipEmail: deferThisEmail`.
  bulkAssign precomputes draftProjectIds for the whole batch.
  autoAssignBulkForRound uses the round's status directly.
- New regression suite (mentor-email-deferral.test.ts, 3 cases):
  vi.mocks @/lib/email, asserts zero outbound sends when round is
  ROUND_DRAFT, confirms in-app notification rows still get written,
  and re-verifies the ACTIVE-round path still emails.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

prisma/migrations/20260526114936_mentor_assignment_team_introduced_at/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "MentorAssignment" ADD COLUMN     "teamIntroducedAt" TIMESTAMP(3);

prisma/schema.prisma

@@ -1281,9 +1281,16 @@ model MentorAssignment {
   assignedAt DateTime               @default(now())
   assignedBy String? // Admin who assigned
 
-  // Per-assignment email idempotency: stamped once the assignment notification email is sent.
+  // Per-assignment email idempotency: stamped once the MENTOR-side notification
+  // email has been sent (the "you've been assigned a project" email to the mentor).
   notificationSentAt DateTime?
 
+  // Stamped once the TEAM has been introduced to this mentor (the "meet your
+  // mentor" email with mentor contact info). Fired by `activateRound` for
+  // MENTORING rounds and by mentor.assign when the project's MENTORING round
+  // is already ROUND_ACTIVE. Independent from notificationSentAt above.
+  teamIntroducedAt DateTime?
+
   // AI assignment metadata
   aiConfidenceScore   Float?
   expertiseMatchScore Float?

src/app/(admin)/admin/members/[id]/page.tsx

@@ -976,17 +976,39 @@ export default function MemberDetailPage() {
               Cancel
             </AlertDialogCancel>
             <AlertDialogAction
-              onClick={() => {
+              onClick={async () => {
                 if (!pendingAdditionalRole) return
                 const { role: r, action } = pendingAdditionalRole
-                if (action === 'add') {
-                  setAdditionalRoles((prev) =>
-                    prev.includes(r) ? prev : [...prev, r]
+                const nextAdditional =
+                  action === 'add'
+                    ? additionalRoles.includes(r)
+                      ? additionalRoles
+                      : [...additionalRoles, r]
+                    : additionalRoles.filter((x) => x !== r)
+                const nextAllRoles = [
+                  role,
+                  ...nextAdditional.filter((x) => x !== role),
+                ] as Array<'SUPER_ADMIN' | 'PROGRAM_ADMIN' | 'JURY_MEMBER' | 'MENTOR' | 'OBSERVER' | 'APPLICANT' | 'AUDIENCE'>
+                try {
+                  await updateUser.mutateAsync({
+                    id: userId,
+                    roles: nextAllRoles,
+                  })
+                  setAdditionalRoles(nextAdditional)
+                  utils.user.get.invalidate({ id: userId })
+                  utils.user.list.invalidate()
+                  toast.success(
+                    action === 'add'
+                      ? `${r.replace(/_/g, ' ')} role added`
+                      : `${r.replace(/_/g, ' ')} role removed`,
                   )
-                } else {
-                  setAdditionalRoles((prev) => prev.filter((x) => x !== r))
-                }
+                } catch (error) {
+                  toast.error(
+                    error instanceof Error ? error.message : 'Failed to update roles',
+                  )
+                } finally {
                   setPendingAdditionalRole(null)
+                }
               }}
             >
               {pendingAdditionalRole?.action === 'add' ? 'Add role' : 'Remove role'}

src/app/(admin)/admin/projects/[id]/mentor/page.tsx

@@ -15,6 +15,7 @@ import {
 import { Button } from '@/components/ui/button'
 import { Badge } from '@/components/ui/badge'
 import { Skeleton } from '@/components/ui/skeleton'
+import { Checkbox } from '@/components/ui/checkbox'
 import { Avatar, AvatarFallback } from '@/components/ui/avatar'
 import { Progress } from '@/components/ui/progress'
 import { Input } from '@/components/ui/input'
@@ -74,6 +75,9 @@ function MentorAssignmentContent({ projectId }: { projectId: string }) {
     assignmentId: string
     mentorName: string
   } | null>(null)
+  const [selectedCandidateIds, setSelectedCandidateIds] = useState<Set<string>>(
+    new Set(),
+  )
 
   const { data: project, isLoading: projectLoading } = trpc.project.get.useQuery({ id: projectId })
 
@@ -111,6 +115,7 @@ function MentorAssignmentContent({ projectId }: { projectId: string }) {
       utils.project.get.invalidate({ id: projectId })
       utils.mentor.getCandidates.invalidate({ projectId })
       utils.mentor.getSuggestions.invalidate({ projectId })
+      utils.mentor.getMentorPool.invalidate()
       setPendingMentorId(null)
     },
     onError: (err) => {
@@ -119,6 +124,30 @@ function MentorAssignmentContent({ projectId }: { projectId: string }) {
     },
   })
 
+  const bulkAssignMutation = trpc.mentor.bulkAssign.useMutation({
+    onSuccess: (result) => {
+      if (result.totalAssigned === 0) {
+        toast.info('No new assignments — every chosen mentor was already on this team.')
+      } else {
+        toast.success(
+          `Added ${result.totalAssigned} mentor${
+            result.totalAssigned === 1 ? '' : 's'
+          } to this team${
+            result.emailsSent > 0
+              ? ` · ${result.emailsSent} email${result.emailsSent === 1 ? '' : 's'} sent`
+              : ' · emails will go out when the mentoring round opens'
+          }`,
+        )
+      }
+      utils.project.get.invalidate({ id: projectId })
+      utils.mentor.getCandidates.invalidate({ projectId })
+      utils.mentor.getSuggestions.invalidate({ projectId })
+      utils.mentor.getMentorPool.invalidate()
+      setSelectedCandidateIds(new Set())
+    },
+    onError: (err) => toast.error(err.message),
+  })
+
   const unassignMutation = trpc.mentor.unassign.useMutation({
     onSuccess: () => {
       toast.success('Mentor removed')
@@ -383,6 +412,41 @@ function MentorAssignmentContent({ projectId }: { projectId: string }) {
                   className="pl-9"
                 />
               </div>
+              {selectedCandidateIds.size > 0 && (
+                <div className="flex flex-col gap-2 rounded-md border border-primary/30 bg-primary/5 px-4 py-2.5 text-sm sm:flex-row sm:items-center sm:justify-between">
+                  <div>
+                    <span className="font-medium">{selectedCandidateIds.size}</span>{' '}
+                    <span className="text-muted-foreground">
+                      mentor{selectedCandidateIds.size === 1 ? '' : 's'} selected
+                    </span>
+                  </div>
+                  <div className="flex flex-wrap gap-2">
+                    <Button
+                      size="sm"
+                      onClick={() =>
+                        bulkAssignMutation.mutate({
+                          mentorIds: Array.from(selectedCandidateIds),
+                          projectIds: [projectId],
+                        })
+                      }
+                      disabled={bulkAssignMutation.isPending}
+                    >
+                      {bulkAssignMutation.isPending && (
+                        <Loader2 className="mr-1.5 h-4 w-4 animate-spin" />
+                      )}
+                      Add {selectedCandidateIds.size} mentor
+                      {selectedCandidateIds.size === 1 ? '' : 's'}
+                    </Button>
+                    <Button
+                      size="sm"
+                      variant="outline"
+                      onClick={() => setSelectedCandidateIds(new Set())}
+                    >
+                      Clear
+                    </Button>
+                  </div>
+                </div>
+              )}
               {candidatesLoading ? (
                 <div className="space-y-2">
                   {[1, 2, 3].map((i) => (
@@ -400,6 +464,28 @@ function MentorAssignmentContent({ projectId }: { projectId: string }) {
                   <Table>
                     <TableHeader>
                       <TableRow>
+                        <TableHead className="w-10">
+                          <Checkbox
+                            checked={
+                              filteredCandidates.length > 0 &&
+                              filteredCandidates.every((c) =>
+                                selectedCandidateIds.has(c.id),
+                              )
+                            }
+                            onCheckedChange={(checked) => {
+                              setSelectedCandidateIds((prev) => {
+                                const next = new Set(prev)
+                                if (checked) {
+                                  filteredCandidates.forEach((c) => next.add(c.id))
+                                } else {
+                                  filteredCandidates.forEach((c) => next.delete(c.id))
+                                }
+                                return next
+                              })
+                            }}
+                            aria-label="Select all visible mentors"
+                          />
+                        </TableHead>
                         <TableHead>Mentor</TableHead>
                         <TableHead>Expertise</TableHead>
                         <TableHead>Country</TableHead>
@@ -410,7 +496,26 @@ function MentorAssignmentContent({ projectId }: { projectId: string }) {
                     </TableHeader>
                     <TableBody>
                       {filteredCandidates.map((c) => (
-                        <TableRow key={c.id}>
+                        <TableRow
+                          key={c.id}
+                          data-state={
+                            selectedCandidateIds.has(c.id) ? 'selected' : undefined
+                          }
+                        >
+                          <TableCell>
+                            <Checkbox
+                              checked={selectedCandidateIds.has(c.id)}
+                              onCheckedChange={(checked) =>
+                                setSelectedCandidateIds((prev) => {
+                                  const next = new Set(prev)
+                                  if (checked) next.add(c.id)
+                                  else next.delete(c.id)
+                                  return next
+                                })
+                              }
+                              aria-label={`Select ${c.name ?? c.email}`}
+                            />
+                          </TableCell>
                           <TableCell>
                             <div className="font-medium">{c.name ?? 'Unnamed'}</div>
                             <div className="text-muted-foreground text-xs">{c.email}</div>

src/app/(admin)/admin/rounds/[roundId]/page.tsx

@@ -92,6 +92,7 @@ import { ProjectStatesTable } from '@/components/admin/round/project-states-tabl
 import { FileRequirementsEditor } from '@/components/admin/round/file-requirements-editor'
 import { FilteringDashboard } from '@/components/admin/round/filtering-dashboard'
 import { MentoringRoundOverview } from '@/components/admin/round/mentoring-round-overview'
+import { MentoringProjectsTable } from '@/components/admin/round/mentoring-projects-table'
 import { FinalistSlotsCard } from '@/components/admin/grand-finale/finalist-slots-card'
 import { WaitlistCard } from '@/components/admin/grand-finale/waitlist-card'
 import { RankingDashboard } from '@/components/admin/round/ranking-dashboard'
@@ -168,6 +169,10 @@ function MentoringBulkAssignToolbar({
     { enabled: !isAdminSelected, refetchInterval: 30_000 },
   )
   const count = pending?.count ?? 0
+  const eligibleTotal = pending?.eligibleTotal ?? 0
+  const mentorPoolSize = pending?.mentorPoolSize ?? 0
+  const hasNoMentors = mentorPoolSize === 0
+  const hasNoEligible = eligibleTotal === 0
 
   const bulk = trpc.mentor.autoAssignBulkForRound.useMutation({
     onSuccess: (result) => {
@@ -190,23 +195,41 @@ function MentoringBulkAssignToolbar({
               — auto-fill is disabled. Assign each project manually.
             </span>
           </>
+        ) : hasNoMentors ? (
+          <span className="text-muted-foreground">
+            No mentors in the pool yet —{' '}
+            <Link
+              href="/admin/members?tab=mentors"
+              className="text-foreground underline-offset-2 hover:underline"
+            >
+              add mentors
+            </Link>{' '}
+            before auto-filling.
+          </span>
+        ) : hasNoEligible ? (
+          <span className="text-muted-foreground">
+            No projects are eligible for mentorship in this round (
+            {eligibilityLabel}).
+          </span>
         ) : count > 0 ? (
           <>
             <span className="font-medium">{count}</span>{' '}
             <span className="text-muted-foreground">
-              project{count === 1 ? '' : 's'} eligible for auto-fill ({eligibilityLabel})
+              of {eligibleTotal} project{eligibleTotal === 1 ? '' : 's'} still
+              needs a mentor ({eligibilityLabel})
             </span>
           </>
         ) : (
           <span className="text-muted-foreground">
-            All eligible projects have a mentor.
+            All {eligibleTotal} eligible project{eligibleTotal === 1 ? '' : 's'}{' '}
+            already have a mentor.
           </span>
         )}
       </div>
       <Button
         size="sm"
         onClick={() => bulk.mutate({ roundId })}
-        disabled={isAdminSelected || count === 0 || bulk.isPending}
+        disabled={isAdminSelected || count === 0 || hasNoMentors || bulk.isPending}
       >
         {bulk.isPending ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : null}
         Auto-fill remaining
@@ -1242,6 +1265,20 @@ export default function RoundDetailPage() {
                 <div>
                   <p className="text-[11px] font-semibold uppercase tracking-wider text-muted-foreground mb-2">Project Management</p>
                   <div className="grid gap-3 sm:grid-cols-2 lg:grid-cols-3">
+                    {isMentoring ? (
+                      <button
+                        onClick={() => setActiveTab('projects')}
+                        className="flex items-start gap-3 p-4 rounded-lg border hover:-translate-y-0.5 hover:shadow-md transition-all text-left w-full"
+                      >
+                        <Layers className="h-5 w-5 text-[#557f8c] mt-0.5 shrink-0" />
+                        <div>
+                          <p className="text-sm font-medium">Assign Projects</p>
+                          <p className="text-xs text-muted-foreground mt-0.5">
+                            Open the Projects tab to add or auto-fill teams in this round
+                          </p>
+                        </div>
+                      </button>
+                    ) : (
                       <Link href={poolLink}>
                         <button className="flex items-start gap-3 p-4 rounded-lg border hover:-translate-y-0.5 hover:shadow-md transition-all text-left w-full">
                           <Layers className="h-5 w-5 text-[#557f8c] mt-0.5 shrink-0" />
@@ -1253,6 +1290,7 @@ export default function RoundDetailPage() {
                           </div>
                         </button>
                       </Link>
+                    )}
 
                     <button
                       onClick={() => setActiveTab('projects')}
@@ -1570,8 +1608,17 @@ export default function RoundDetailPage() {
         {/* ═══════════ PROJECTS TAB ═══════════ */}
         <TabsContent value="projects" className="space-y-4">
           {isMentoring && (
+            <>
               <MentoringBulkAssignToolbar roundId={roundId} configJson={config} />
+              <MentoringProjectsTable
+                roundId={roundId}
+                competitionId={competitionId}
+                competitionRounds={competition?.rounds}
+                currentSortOrder={round?.sortOrder}
+              />
+            </>
           )}
+          {!isMentoring && (
             <ProjectStatesTable
               competitionId={competitionId}
               roundId={roundId}
@@ -1583,6 +1630,7 @@ export default function RoundDetailPage() {
                 setTimeout(() => setPreviewSheetOpen(true), 100)
               }}
             />
+          )}
         </TabsContent>
 
         {/* ═══════════ FILTERING TAB ═══════════ */}

src/app/(applicant)/applicant/team/page.tsx

@@ -357,15 +357,33 @@ export default function ApplicantProjectPage() {
             )}
           </div>
 
-          {/* Mentor info — TODO(PR8 Task 7): list ALL assigned mentors */}
-          {project.mentorAssignments?.[0]?.mentor && (
+          {(() => {
+            type MentorAssignment = {
+              droppedAt: Date | string | null
+              mentor: { name: string | null; email: string } | null
+            }
+            const active = (
+              (project.mentorAssignments as MentorAssignment[] | undefined) ?? []
+            ).filter((a) => !a.droppedAt && a.mentor)
+            if (active.length === 0) return null
+            return (
               <div className="rounded-lg border p-3 bg-muted/50">
-              <p className="text-sm font-medium mb-1">Assigned Mentor</p>
-              <p className="text-sm text-muted-foreground">
-                {project.mentorAssignments[0].mentor.name} ({project.mentorAssignments[0].mentor.email})
+                <p className="text-sm font-medium mb-1">
+                  {active.length === 1 ? 'Assigned Mentor' : `Assigned Mentors (${active.length})`}
                 </p>
-            </div>
+                <ul className="space-y-0.5">
+                  {active.map((a, idx) => (
+                    <li key={`${a.mentor!.email}-${idx}`} className="text-sm text-muted-foreground">
+                      {a.mentor!.name ?? a.mentor!.email}
+                      {a.mentor!.name && (
+                        <span className="text-xs"> ({a.mentor!.email})</span>
                       )}
+                    </li>
+                  ))}
+                </ul>
+              </div>
+            )
+          })()}
 
           {/* Tags */}
           {project.tags && project.tags.length > 0 && (

src/components/admin/round/mentoring-projects-table.tsx

@@ -0,0 +1,738 @@
+'use client'
+
+import { useMemo, useState } from 'react'
+import Link from 'next/link'
+import { toast } from 'sonner'
+import { trpc } from '@/lib/trpc/client'
+import {
+  Table,
+  TableBody,
+  TableCell,
+  TableHead,
+  TableHeader,
+  TableRow,
+} from '@/components/ui/table'
+import { Badge } from '@/components/ui/badge'
+import { Button } from '@/components/ui/button'
+import { Input } from '@/components/ui/input'
+import { Skeleton } from '@/components/ui/skeleton'
+import { Checkbox } from '@/components/ui/checkbox'
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from '@/components/ui/dialog'
+import {
+  Search,
+  UserPlus,
+  ArrowRight,
+  Sparkles,
+  Loader2,
+  Download,
+  X,
+  Plus,
+} from 'lucide-react'
+import { CountryDisplay } from '@/components/shared/country-display'
+import { AddProjectDialog } from '@/components/admin/round/project-states-table'
+
+type Filter = 'all' | 'unassigned' | 'assigned' | 'wants_only'
+
+type CompetitionRound = {
+  id: string
+  name: string
+  sortOrder: number
+  _count: { projectRoundStates: number }
+}
+
+export function MentoringProjectsTable({
+  roundId,
+  competitionId,
+  competitionRounds,
+  currentSortOrder,
+}: {
+  roundId: string
+  competitionId: string
+  competitionRounds?: CompetitionRound[]
+  currentSortOrder?: number
+}) {
+  const [addProjectOpen, setAddProjectOpen] = useState(false)
+  const [search, setSearch] = useState('')
+  const [filter, setFilter] = useState<Filter>('all')
+  const [selected, setSelected] = useState<Set<string>>(new Set())
+  const [bulkOpen, setBulkOpen] = useState(false)
+  const [chosenMentorIds, setChosenMentorIds] = useState<Set<string>>(new Set())
+  const [mentorSearch, setMentorSearch] = useState('')
+
+  const utils = trpc.useUtils()
+
+  const { data, isLoading } = trpc.round.listMentoringProjects.useQuery(
+    { roundId },
+    { refetchInterval: 30_000 },
+  )
+
+  const { data: importCandidates } =
+    trpc.round.getMentoringImportCandidates.useQuery({ roundId })
+
+  const { data: mentorPool } = trpc.mentor.getMentorPool.useQuery(
+    {},
+    { enabled: bulkOpen },
+  )
+
+  const bulkAssignMutation = trpc.mentor.bulkAssign.useMutation({
+    onSuccess: (result) => {
+      if (result.totalAssigned === 0 && result.totalSkipped > 0) {
+        toast.info(
+          `No new assignments — every selected mentor is already on every selected project (${result.totalSkipped} pair${result.totalSkipped === 1 ? '' : 's'} skipped).`,
+        )
+      } else if (result.totalAssigned === 0 && result.ineligibleProjectCount > 0) {
+        toast.warning(
+          `${result.ineligibleProjectCount} project${result.ineligibleProjectCount === 1 ? '' : 's'} aren't in a mentoring round and were skipped.`,
+        )
+      } else {
+        const mentorCount = result.perMentor.filter((m) => m.assigned > 0).length
+        toast.success(
+          `Created ${result.totalAssigned} assignment${
+            result.totalAssigned === 1 ? '' : 's'
+          } across ${result.touchedProjectCount} project${
+            result.touchedProjectCount === 1 ? '' : 's'
+          }${result.totalSkipped > 0 ? ` (${result.totalSkipped} pair${result.totalSkipped === 1 ? '' : 's'} already existed)` : ''}${
+            result.emailsSent > 0
+              ? ` · ${result.emailsSent} mentor email${result.emailsSent === 1 ? '' : 's'} sent`
+              : ''
+          }`,
+          {
+            description:
+              mentorCount > 1
+                ? `Each of ${mentorCount} mentors gets a single combined email listing only their new projects.`
+                : undefined,
+          },
+        )
+      }
+      utils.round.listMentoringProjects.invalidate({ roundId })
+      utils.round.getProjectsNeedingMentor.invalidate({ roundId })
+      utils.round.getMentoringImportCandidates.invalidate({ roundId })
+      utils.mentor.getMentorPool.invalidate()
+      utils.mentor.getRoundStats.invalidate({ roundId })
+      utils.project.list.invalidate()
+      setSelected(new Set())
+      setChosenMentorIds(new Set())
+      setMentorSearch('')
+      setBulkOpen(false)
+    },
+    onError: (err) => toast.error(err.message),
+  })
+
+  const advanceMutation = trpc.round.advanceProjects.useMutation({
+    onSuccess: (result) => {
+      toast.success(
+        `Imported ${result.advancedCount} project${
+          result.advancedCount === 1 ? '' : 's'
+        } from ${result.targetRoundName ? '' : ''}${
+          importCandidates?.priorRound?.name ?? 'the prior round'
+        }`,
+      )
+      utils.round.listMentoringProjects.invalidate({ roundId })
+      utils.round.getMentoringImportCandidates.invalidate({ roundId })
+      utils.round.getProjectsNeedingMentor.invalidate({ roundId })
+    },
+    onError: (err) => toast.error(err.message),
+  })
+
+  const importBanner = importCandidates?.priorRound &&
+    importCandidates.pendingCount > 0 && (
+      <div className="flex flex-col gap-2 rounded-md border border-amber-300 bg-amber-50 px-4 py-3 text-sm sm:flex-row sm:items-center sm:justify-between">
+        <div className="text-amber-900">
+          <span className="font-medium">
+            {importCandidates.pendingCount} PASSED project
+            {importCandidates.pendingCount === 1 ? '' : 's'}
+          </span>{' '}
+          from{' '}
+          <span className="font-medium">
+            {importCandidates.priorRound.name}
+          </span>{' '}
+          {importCandidates.pendingCount === 1 ? "isn't" : "aren't"} in this
+          mentoring round yet.
+        </div>
+        <Button
+          size="sm"
+          onClick={() =>
+            advanceMutation.mutate({
+              roundId: importCandidates.priorRound!.id,
+              targetRoundId: roundId,
+            })
+          }
+          disabled={advanceMutation.isPending}
+        >
+          {advanceMutation.isPending ? (
+            <Loader2 className="mr-1.5 h-4 w-4 animate-spin" />
+          ) : (
+            <Download className="mr-1.5 h-4 w-4" />
+          )}
+          Import {importCandidates.pendingCount}
+        </Button>
+      </div>
+    )
+
+  const filtered = useMemo(() => {
+    if (!data) return []
+    const q = search.trim().toLowerCase()
+    return data.projects.filter((p) => {
+      if (filter === 'unassigned' && p.mentors.length > 0) return false
+      if (filter === 'assigned' && p.mentors.length === 0) return false
+      if (filter === 'wants_only' && !p.wantsMentorship) return false
+      if (!q) return true
+      const hay = [
+        p.title,
+        p.teamName ?? '',
+        p.country ?? '',
+        ...p.mentors.map((m) => m.name ?? m.email),
+      ]
+        .join(' ')
+        .toLowerCase()
+      return hay.includes(q)
+    })
+  }, [data, search, filter])
+
+  const totals = useMemo(() => {
+    if (!data)
+      return { total: 0, unassigned: 0, assigned: 0, wants: 0 }
+    return {
+      total: data.projects.length,
+      unassigned: data.projects.filter((p) => p.mentors.length === 0).length,
+      assigned: data.projects.filter((p) => p.mentors.length > 0).length,
+      wants: data.projects.filter((p) => p.wantsMentorship).length,
+    }
+  }, [data])
+
+  if (isLoading) {
+    return (
+      <div className="space-y-2">
+        {[1, 2, 3, 4, 5].map((i) => (
+          <Skeleton key={i} className="h-14 w-full" />
+        ))}
+      </div>
+    )
+  }
+
+  if (!data || data.projects.length === 0) {
+    return (
+      <div className="space-y-3">
+        {importBanner}
+        <div className="flex items-center justify-end">
+          <Button size="sm" onClick={() => setAddProjectOpen(true)}>
+            <Plus className="mr-1.5 h-4 w-4" />
+            Add Project to Round
+          </Button>
+        </div>
+        <div className="rounded-md border bg-muted/30 px-4 py-12 text-center text-sm text-muted-foreground">
+          No projects in this mentoring round yet. Click{' '}
+          <span className="font-medium text-foreground">Add Project to Round</span>{' '}
+          above to populate it.
+        </div>
+
+        <AddProjectDialog
+          open={addProjectOpen}
+          onOpenChange={setAddProjectOpen}
+          roundId={roundId}
+          competitionId={competitionId}
+          competitionRounds={competitionRounds}
+          currentSortOrder={currentSortOrder}
+          onAssigned={() => {
+            utils.round.listMentoringProjects.invalidate({ roundId })
+            utils.round.getProjectsNeedingMentor.invalidate({ roundId })
+            utils.round.getMentoringImportCandidates.invalidate({ roundId })
+            utils.mentor.getRoundStats.invalidate({ roundId })
+          }}
+        />
+      </div>
+    )
+  }
+
+  const Pill = ({
+    value,
+    label,
+    count,
+  }: {
+    value: Filter
+    label: string
+    count: number
+  }) => (
+    <button
+      type="button"
+      onClick={() => setFilter(value)}
+      className={`rounded-md border px-2.5 py-1 text-xs font-medium transition-colors ${
+        filter === value
+          ? 'border-primary bg-primary text-primary-foreground'
+          : 'bg-background hover:bg-muted'
+      }`}
+    >
+      {label}{' '}
+      <span className="tabular-nums opacity-80">({count})</span>
+    </button>
+  )
+
+  return (
+    <div className="space-y-3">
+      {importBanner}
+      <div className="flex flex-col gap-2 sm:flex-row sm:items-center sm:justify-between">
+        <div className="flex flex-wrap gap-1.5">
+          <Pill value="all" label="All" count={totals.total} />
+          <Pill value="unassigned" label="No mentor" count={totals.unassigned} />
+          <Pill value="assigned" label="Has mentor" count={totals.assigned} />
+          <Pill value="wants_only" label="Wants mentorship" count={totals.wants} />
+        </div>
+        <div className="flex items-center gap-2">
+          <div className="relative w-full sm:w-72">
+            <Search className="absolute left-2.5 top-1/2 h-3.5 w-3.5 -translate-y-1/2 text-muted-foreground" />
+            <Input
+              value={search}
+              onChange={(e) => setSearch(e.target.value)}
+              placeholder="Search projects, teams, or mentors…"
+              className="pl-8"
+            />
+          </div>
+          <Button
+            size="sm"
+            onClick={() => setAddProjectOpen(true)}
+            className="shrink-0"
+          >
+            <Plus className="mr-1 h-4 w-4" />
+            Add
+          </Button>
+        </div>
+      </div>
+
+      {selected.size > 0 ? (
+        <div className="flex flex-col gap-2 rounded-md border border-primary/30 bg-primary/5 px-4 py-2.5 text-sm sm:flex-row sm:items-center sm:justify-between">
+          <div>
+            <span className="font-medium">{selected.size}</span>{' '}
+            <span className="text-muted-foreground">
+              project{selected.size === 1 ? '' : 's'} selected
+            </span>
+          </div>
+          <div className="flex flex-wrap gap-2">
+            <Button size="sm" onClick={() => setBulkOpen(true)}>
+              <UserPlus className="mr-1.5 h-4 w-4" />
+              Assign mentor…
+            </Button>
+            <Button
+              size="sm"
+              variant="outline"
+              onClick={() => setSelected(new Set())}
+            >
+              <X className="mr-1 h-4 w-4" />
+              Clear
+            </Button>
+          </div>
+        </div>
+      ) : (
+        <div className="flex items-center justify-between rounded-md border border-dashed bg-muted/20 px-4 py-2 text-xs text-muted-foreground">
+          <span>
+            Tip: tick checkboxes to bulk-assign one mentor to multiple
+            projects in a single click (mentor gets one combined email).
+          </span>
+          {totals.unassigned > 0 && (
+            <button
+              type="button"
+              className="text-xs font-medium text-foreground hover:underline"
+              onClick={() => {
+                setFilter('unassigned')
+                setSelected(
+                  new Set(
+                    data.projects
+                      .filter((p) => p.mentors.length === 0)
+                      .map((p) => p.id),
+                  ),
+                )
+              }}
+            >
+              Select all {totals.unassigned} without a mentor
+            </button>
+          )}
+        </div>
+      )}
+
+      <div className="overflow-hidden rounded-md border">
+        <Table>
+          <TableHeader>
+            <TableRow>
+              <TableHead className="w-10">
+                <Checkbox
+                  checked={
+                    filtered.length > 0 &&
+                    filtered.every((p) => selected.has(p.id))
+                  }
+                  onCheckedChange={(checked) => {
+                    setSelected((prev) => {
+                      const next = new Set(prev)
+                      if (checked) {
+                        filtered.forEach((p) => next.add(p.id))
+                      } else {
+                        filtered.forEach((p) => next.delete(p.id))
+                      }
+                      return next
+                    })
+                  }}
+                  aria-label="Select all visible"
+                />
+              </TableHead>
+              <TableHead>Project</TableHead>
+              <TableHead>Wants?</TableHead>
+              <TableHead>Mentors</TableHead>
+              <TableHead className="w-32 text-right">Action</TableHead>
+            </TableRow>
+          </TableHeader>
+          <TableBody>
+            {filtered.length === 0 ? (
+              <TableRow>
+                <TableCell
+                  colSpan={5}
+                  className="py-8 text-center text-sm text-muted-foreground"
+                >
+                  No projects match the current filter.
+                </TableCell>
+              </TableRow>
+            ) : (
+              filtered.map((p) => (
+                <TableRow
+                  key={p.id}
+                  data-state={selected.has(p.id) ? 'selected' : undefined}
+                >
+                  <TableCell>
+                    <Checkbox
+                      checked={selected.has(p.id)}
+                      onCheckedChange={(checked) =>
+                        setSelected((prev) => {
+                          const next = new Set(prev)
+                          if (checked) next.add(p.id)
+                          else next.delete(p.id)
+                          return next
+                        })
+                      }
+                      aria-label={`Select ${p.title}`}
+                    />
+                  </TableCell>
+                  <TableCell>
+                    <div className="font-medium">{p.title}</div>
+                    <div className="text-xs text-muted-foreground">
+                      {p.teamName ?? '—'}
+                      {p.country && (
+                        <>
+                          {' · '}
+                          <CountryDisplay country={p.country} />
+                        </>
+                      )}
+                    </div>
+                  </TableCell>
+                  <TableCell>
+                    <div className="flex flex-col gap-1">
+                      {p.wantsMentorship ? (
+                        <Badge variant="secondary" className="w-fit text-xs">
+                          Requested
+                        </Badge>
+                      ) : (
+                        <span className="text-xs text-muted-foreground">No</span>
+                      )}
+                      {p.finalistConfirmationStatus !== 'CONFIRMED' && (
+                        <span
+                          className="text-[10px] uppercase tracking-wide text-amber-700"
+                          title="Auto-fill skips projects whose team has not confirmed attendance."
+                        >
+                          {p.finalistConfirmationStatus
+                            ? p.finalistConfirmationStatus.toLowerCase()
+                            : 'no confirmation'}
+                        </span>
+                      )}
+                    </div>
+                  </TableCell>
+                  <TableCell>
+                    {p.mentors.length === 0 ? (
+                      <span className="text-xs italic text-muted-foreground">
+                        Unassigned
+                      </span>
+                    ) : (
+                      <div className="flex flex-wrap gap-1">
+                        {p.mentors.map((m) => (
+                          <Badge
+                            key={m.assignmentId}
+                            variant="outline"
+                            className="gap-1 text-xs"
+                            title={m.email}
+                          >
+                            {(m.method === 'AI_AUTO' ||
+                              m.method === 'AI_SUGGESTED') && (
+                              <Sparkles className="h-3 w-3 text-amber-500" />
+                            )}
+                            {m.name ?? m.email}
+                          </Badge>
+                        ))}
+                      </div>
+                    )}
+                  </TableCell>
+                  <TableCell className="text-right">
+                    <Button asChild size="sm" variant="outline">
+                      <Link href={`/admin/projects/${p.id}/mentor`}>
+                        {p.mentors.length === 0 ? (
+                          <>
+                            <UserPlus className="mr-1 h-3.5 w-3.5" />
+                            Assign
+                          </>
+                        ) : (
+                          <>
+                            Open
+                            <ArrowRight className="ml-1 h-3.5 w-3.5" />
+                          </>
+                        )}
+                      </Link>
+                    </Button>
+                  </TableCell>
+                </TableRow>
+              ))
+            )}
+          </TableBody>
+        </Table>
+      </div>
+
+      <Dialog
+        open={bulkOpen}
+        onOpenChange={(next) => {
+          if (!next) {
+            setBulkOpen(false)
+            setChosenMentorIds(new Set())
+            setMentorSearch('')
+          }
+        }}
+      >
+        <DialogContent>
+          <DialogHeader>
+            <DialogTitle>
+              Assign mentors to {selected.size} project
+              {selected.size === 1 ? '' : 's'}
+            </DialogTitle>
+            <DialogDescription>
+              Tick any number of mentors. Each chosen mentor will be added to
+              every selected project they aren&apos;t already on. Each mentor
+              receives one combined email; each team receives one intro email
+              listing all of their mentors.
+            </DialogDescription>
+          </DialogHeader>
+
+          <div className="space-y-3">
+            {(() => {
+              const allMentors = mentorPool?.mentors ?? []
+              const chosenMentors = allMentors.filter((m) =>
+                chosenMentorIds.has(m.id),
+              )
+              const upperBound = chosenMentorIds.size * selected.size
+
+              return (
+                <>
+                  {chosenMentors.length > 0 && (
+                    <div className="flex flex-wrap gap-1 rounded-md border bg-muted/30 p-2">
+                      {chosenMentors.map((m) => (
+                        <Badge
+                          key={m.id}
+                          variant="secondary"
+                          className="gap-1 pl-2 pr-1"
+                        >
+                          {m.name ?? m.email}
+                          <button
+                            type="button"
+                            aria-label={`Remove ${m.name ?? m.email}`}
+                            className="rounded-full p-0.5 hover:bg-foreground/10"
+                            onClick={() =>
+                              setChosenMentorIds((prev) => {
+                                const next = new Set(prev)
+                                next.delete(m.id)
+                                return next
+                              })
+                            }
+                          >
+                            <X className="h-3 w-3" />
+                          </button>
+                        </Badge>
+                      ))}
+                    </div>
+                  )}
+
+                  <div className="relative">
+                    <Search className="absolute left-2.5 top-1/2 h-3.5 w-3.5 -translate-y-1/2 text-muted-foreground" />
+                    <Input
+                      value={mentorSearch}
+                      onChange={(e) => setMentorSearch(e.target.value)}
+                      placeholder="Search mentor by name, email, country, or expertise…"
+                      className="pl-8"
+                    />
+                  </div>
+
+                  <div className="max-h-72 overflow-y-auto rounded-md border">
+                    {(() => {
+                      const q = mentorSearch.trim().toLowerCase()
+                      const filteredMentors = q
+                        ? allMentors.filter((m) =>
+                            [
+                              m.name ?? '',
+                              m.email,
+                              m.country ?? '',
+                              ...(m.expertiseTags ?? []),
+                            ]
+                              .join(' ')
+                              .toLowerCase()
+                              .includes(q),
+                          )
+                        : allMentors
+                      if (allMentors.length === 0) {
+                        return (
+                          <p className="p-4 text-center text-sm text-muted-foreground">
+                            No mentors in the pool yet.{' '}
+                            <Link
+                              href="/admin/members?tab=mentors"
+                              className="underline-offset-2 hover:underline"
+                            >
+                              Add mentors
+                            </Link>
+                            .
+                          </p>
+                        )
+                      }
+                      if (filteredMentors.length === 0) {
+                        return (
+                          <p className="p-4 text-center text-sm text-muted-foreground">
+                            No mentors match &ldquo;{mentorSearch}&rdquo;.
+                          </p>
+                        )
+                      }
+                      return filteredMentors.map((m) => {
+                        const isChosen = chosenMentorIds.has(m.id)
+                        return (
+                          <label
+                            key={m.id}
+                            className={`flex cursor-pointer items-start gap-3 border-b px-3 py-2 text-sm last:border-b-0 ${
+                              isChosen ? 'bg-accent' : 'hover:bg-muted/50'
+                            }`}
+                          >
+                            <Checkbox
+                              className="mt-1"
+                              checked={isChosen}
+                              onCheckedChange={(checked) =>
+                                setChosenMentorIds((prev) => {
+                                  const next = new Set(prev)
+                                  if (checked) next.add(m.id)
+                                  else next.delete(m.id)
+                                  return next
+                                })
+                              }
+                              aria-label={`Toggle ${m.name ?? m.email}`}
+                            />
+                            <div className="min-w-0 flex-1">
+                              <div className="font-medium">
+                                {m.name ?? 'Unnamed'}
+                              </div>
+                              <div className="truncate text-xs text-muted-foreground">
+                                {m.email}
+                                {m.country && <> · {m.country}</>}
+                              </div>
+                              {m.expertiseTags && m.expertiseTags.length > 0 && (
+                                <div className="mt-1 flex flex-wrap gap-1">
+                                  {m.expertiseTags.slice(0, 4).map((t) => (
+                                    <Badge
+                                      key={t}
+                                      variant="secondary"
+                                      className="text-[10px]"
+                                    >
+                                      {t}
+                                    </Badge>
+                                  ))}
+                                  {m.expertiseTags.length > 4 && (
+                                    <Badge
+                                      variant="outline"
+                                      className="text-[10px]"
+                                    >
+                                      +{m.expertiseTags.length - 4}
+                                    </Badge>
+                                  )}
+                                </div>
+                              )}
+                            </div>
+                            <div className="shrink-0 text-right text-xs tabular-nums text-muted-foreground">
+                              {m.currentAssignments}
+                              {m.maxAssignments != null && `/${m.maxAssignments}`}{' '}
+                              load
+                            </div>
+                          </label>
+                        )
+                      })
+                    })()}
+                  </div>
+
+                  {chosenMentorIds.size > 0 && (
+                    <p className="text-xs text-muted-foreground">
+                      Will create up to{' '}
+                      <span className="font-medium tabular-nums text-foreground">
+                        {upperBound}
+                      </span>{' '}
+                      assignment{upperBound === 1 ? '' : 's'} (
+                      {chosenMentorIds.size} mentor
+                      {chosenMentorIds.size === 1 ? '' : 's'} × {selected.size}{' '}
+                      project{selected.size === 1 ? '' : 's'}). Pairs that
+                      already exist are skipped.
+                    </p>
+                  )}
+                </>
+              )
+            })()}
+          </div>
+
+          <DialogFooter>
+            <Button
+              variant="outline"
+              onClick={() => {
+                setBulkOpen(false)
+                setChosenMentorIds(new Set())
+                setMentorSearch('')
+              }}
+            >
+              Cancel
+            </Button>
+            <Button
+              onClick={() =>
+                bulkAssignMutation.mutate({
+                  mentorIds: Array.from(chosenMentorIds),
+                  projectIds: Array.from(selected),
+                })
+              }
+              disabled={
+                chosenMentorIds.size === 0 || bulkAssignMutation.isPending
+              }
+            >
+              {bulkAssignMutation.isPending && (
+                <Loader2 className="mr-1.5 h-4 w-4 animate-spin" />
+              )}
+              Assign {chosenMentorIds.size} mentor
+              {chosenMentorIds.size === 1 ? '' : 's'} to {selected.size} project
+              {selected.size === 1 ? '' : 's'}
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
+
+      <AddProjectDialog
+        open={addProjectOpen}
+        onOpenChange={setAddProjectOpen}
+        roundId={roundId}
+        competitionId={competitionId}
+        competitionRounds={competitionRounds}
+        currentSortOrder={currentSortOrder}
+        onAssigned={() => {
+          utils.round.listMentoringProjects.invalidate({ roundId })
+          utils.round.getProjectsNeedingMentor.invalidate({ roundId })
+          utils.round.getMentoringImportCandidates.invalidate({ roundId })
+          utils.mentor.getRoundStats.invalidate({ roundId })
+        }}
+      />
+    </div>
+  )
+}

src/components/admin/round/project-states-table.tsx

@@ -785,7 +785,7 @@ function QuickAddDialog({
  * Create New: form to create a project and assign it directly to the round.
  * From Pool: search existing projects not yet in this round and assign them.
  */
-function AddProjectDialog({
+export function AddProjectDialog({
   open,
   onOpenChange,
   roundId,

src/components/ui/dialog.tsx

@@ -34,7 +34,7 @@ const DialogContent = React.forwardRef<
     <DialogPrimitive.Content
       ref={ref}
       className={cn(
-        'fixed left-[50%] top-[50%] z-50 grid w-full max-w-lg translate-x-[-50%] translate-y-[-50%] gap-4 border bg-background p-6 shadow-lg duration-200 data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95 sm:rounded-lg',
+        'fixed left-[50%] top-[50%] z-50 flex max-h-[90vh] w-full max-w-lg translate-x-[-50%] translate-y-[-50%] flex-col gap-4 overflow-y-auto border bg-background p-6 shadow-lg duration-200 data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95 sm:rounded-lg',
         className
       )}
       {...props}

src/lib/email.ts

@@ -9,6 +9,12 @@ import { prisma } from '@/lib/prisma'
 const DEV_EMAIL_OVERRIDE = process.env.DEV_EMAIL_OVERRIDE || ''
 
 async function sendEmail(opts: { to: string; subject: string; text: string; html: string }): Promise<void> {
+  // Hard guard: never send real email from the test runner. This is a belt-and-
+  // braces check on top of the vitest-level mock in tests/setup.ts. Vitest sets
+  // NODE_ENV='test' and exposes VITEST=true automatically.
+  if (process.env.NODE_ENV === 'test' || process.env.VITEST === 'true') {
+    return
+  }
   const { transporter, from } = await getTransporter()
   const to = DEV_EMAIL_OVERRIDE || opts.to
   const subject = DEV_EMAIL_OVERRIDE ? `[DEV → ${opts.to}] ${opts.subject}` : opts.subject
@@ -2826,6 +2832,217 @@ export async function sendMentorTeamAssignmentEmail(
   }
 }
 
+function getTeamMentorIntroductionTemplate(
+  recipientName: string | null,
+  projectTitle: string,
+  mentors: { name: string | null; email: string }[],
+  workspaceUrl: string,
+): EmailTemplate {
+  const count = mentors.length
+  const subject =
+    count === 1
+      ? `Your mentor for "${projectTitle}" on MOPC`
+      : `Your ${count} mentors for "${projectTitle}" on MOPC`
+  const greeting = recipientName ? `Hi ${recipientName},` : 'Hi there,'
+
+  const mentorTextLines = mentors
+    .map(
+      (m) => `  • ${m.name ?? 'Mentor'} — ${m.email}`,
+    )
+    .join('\n')
+
+  const text = [
+    greeting,
+    '',
+    count === 1
+      ? `The mentoring round is now open, and your project "${projectTitle}" has a mentor:`
+      : `The mentoring round is now open, and your project "${projectTitle}" has ${count} mentors:`,
+    '',
+    mentorTextLines,
+    '',
+    'You can chat with them, share files, and track milestones in your mentor workspace:',
+    workspaceUrl,
+    '',
+    'Feel free to reach out to them directly by email as well.',
+    '',
+    'The MOPC team',
+  ].join('\n')
+
+  const mentorHtmlList = mentors
+    .map(
+      (m) => `
+        <tr>
+          <td style="padding:6px 0;font-weight:600;color:#0f172a;">${escapeHtml(m.name ?? 'Mentor')}</td>
+          <td style="padding:6px 0;">
+            <a href="mailto:${escapeHtml(m.email)}" style="color:#053d57;text-decoration:none;">${escapeHtml(m.email)}</a>
+          </td>
+        </tr>`,
+    )
+    .join('')
+
+  const html = `
+<!DOCTYPE html>
+<html>
+<body style="margin:0;padding:0;background:#f6f8fa;font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Helvetica,Arial,sans-serif;color:#0f172a;">
+  <div style="max-width:560px;margin:32px auto;background:#fff;border-radius:8px;overflow:hidden;box-shadow:0 1px 3px rgba(0,0,0,0.06);">
+    <div style="background:#053d57;padding:24px 28px;color:#fefefe;">
+      <h1 style="margin:0;font-size:20px;font-weight:600;">${count === 1 ? 'Meet your mentor' : `Meet your ${count} mentors`}</h1>
+    </div>
+    <div style="padding:24px 28px;line-height:1.5;font-size:14px;">
+      <p style="margin-top:0;">${recipientName ? `Hi ${escapeHtml(recipientName)},` : 'Hi there,'}</p>
+      <p>${count === 1
+        ? `The mentoring round is now open and a mentor has been assigned to your project <strong>${escapeHtml(projectTitle)}</strong>:`
+        : `The mentoring round is now open and <strong>${count}</strong> mentors have been assigned to your project <strong>${escapeHtml(projectTitle)}</strong>:`}</p>
+      <table style="width:100%;border-collapse:collapse;margin:12px 0 20px;font-size:14px;">${mentorHtmlList}</table>
+      <p style="margin-top:24px;">
+        <a href="${workspaceUrl}" style="display:inline-block;padding:10px 20px;background:#de0f1e;color:#fff;text-decoration:none;border-radius:6px;font-weight:600;">Open Mentor Workspace</a>
+      </p>
+      <p style="margin-top:24px;color:#64748b;font-size:12px;">
+        You can chat with them, share files, and track milestones in the workspace — or reach out to them directly by email.
+      </p>
+    </div>
+    <div style="padding:16px 28px;background:#f1f5f9;color:#64748b;font-size:12px;text-align:center;">
+      Monaco Ocean Protection Challenge
+    </div>
+  </div>
+</body>
+</html>
+  `.trim()
+
+  return { subject, text, html }
+}
+
+/**
+ * Introduce a project team to their assigned mentor(s), with each mentor's
+ * name + email so the team can reach out directly. Sent when the MENTORING
+ * round opens AND any time a mentor is added to a project whose mentoring
+ * round is already open. Never throws.
+ */
+export async function sendTeamMentorIntroductionEmail(
+  recipientEmail: string,
+  recipientName: string | null,
+  projectTitle: string,
+  projectId: string,
+  mentors: { name: string | null; email: string }[],
+): Promise<void> {
+  try {
+    if (mentors.length === 0) return
+    const baseUrl = (process.env.NEXTAUTH_URL || 'https://monaco-opc.com').replace(/\/$/, '')
+    const workspaceUrl = `${baseUrl}/applicant/mentor`
+    const template = getTeamMentorIntroductionTemplate(
+      recipientName,
+      projectTitle,
+      mentors,
+      workspaceUrl,
+    )
+    await sendEmail({
+      to: recipientEmail,
+      subject: template.subject,
+      text: template.text,
+      html: template.html,
+    })
+  } catch (error) {
+    console.error('[sendTeamMentorIntroductionEmail] failed', { recipientEmail, projectId, error })
+  }
+}
+
+function getMentorBulkAssignmentTemplate(
+  name: string,
+  projects: { title: string; url: string }[],
+  mentorDashboardUrl: string,
+): EmailTemplate {
+  const count = projects.length
+  const subject =
+    count === 1
+      ? `You've been assigned to a new MOPC project: "${projects[0].title}"`
+      : `You've been assigned to ${count} new MOPC projects`
+  const greeting = name ? `Hi ${name},` : 'Hi there,'
+
+  const textLines = projects
+    .map((p) => `  • ${p.title} — ${p.url}`)
+    .join('\n')
+  const text = [
+    greeting,
+    '',
+    count === 1
+      ? `You have been assigned as a mentor to a new project:`
+      : `You have been assigned as a mentor to ${count} new projects:`,
+    '',
+    textLines,
+    '',
+    'You may have co-mentors on these teams — you can collaborate together in each project workspace.',
+    '',
+    `Open your mentor dashboard: ${mentorDashboardUrl}`,
+    '',
+    'The MOPC team',
+  ].join('\n')
+
+  const htmlList = projects
+    .map(
+      (p) =>
+        `<li style="margin:6px 0;"><a href="${p.url}" style="color:#053d57;text-decoration:none;font-weight:600;">${escapeHtml(p.title)}</a></li>`,
+    )
+    .join('')
+
+  const html = `
+<!DOCTYPE html>
+<html>
+<body style="margin:0;padding:0;background:#f6f8fa;font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Helvetica,Arial,sans-serif;color:#0f172a;">
+  <div style="max-width:560px;margin:32px auto;background:#fff;border-radius:8px;overflow:hidden;box-shadow:0 1px 3px rgba(0,0,0,0.06);">
+    <div style="background:#053d57;padding:24px 28px;color:#fefefe;">
+      <h1 style="margin:0;font-size:20px;font-weight:600;">${count === 1 ? 'New mentor assignment' : `${count} new mentor assignments`}</h1>
+    </div>
+    <div style="padding:24px 28px;line-height:1.5;font-size:14px;">
+      <p style="margin-top:0;">${name ? `Hi ${escapeHtml(name)},` : 'Hi there,'}</p>
+      <p>${count === 1 ? 'You have been assigned as a mentor to a new project:' : `You have been assigned as a mentor to <strong>${count}</strong> new projects:`}</p>
+      <ul style="padding-left:20px;margin:12px 0 20px;">${htmlList}</ul>
+      <p style="margin-top:24px;">
+        <a href="${mentorDashboardUrl}" style="display:inline-block;padding:10px 20px;background:#de0f1e;color:#fff;text-decoration:none;border-radius:6px;font-weight:600;">Open Mentor Dashboard</a>
+      </p>
+      <p style="margin-top:24px;color:#64748b;font-size:12px;">
+        You may have co-mentors on these teams — you can collaborate together in each project workspace.
+      </p>
+    </div>
+    <div style="padding:16px 28px;background:#f1f5f9;color:#64748b;font-size:12px;text-align:center;">
+      Monaco Ocean Protection Challenge
+    </div>
+  </div>
+</body>
+</html>
+  `.trim()
+
+  return { subject, text, html }
+}
+
+/**
+ * Send a coalesced mentor-assignment email when one mentor receives multiple
+ * project assignments in a single bulk operation. Caller passes the list of
+ * NEW assignments (already filtered to exclude any whose notificationSentAt
+ * was previously set). Never throws.
+ */
+export async function sendMentorBulkAssignmentEmail(
+  email: string,
+  name: string | null,
+  projects: { id: string; title: string }[],
+): Promise<void> {
+  try {
+    if (projects.length === 0) return
+    const baseUrl = (process.env.NEXTAUTH_URL || 'https://monaco-opc.com').replace(/\/$/, '')
+    const enriched = projects.map((p) => ({
+      title: p.title,
+      url: `${baseUrl}/mentor/workspace/${p.id}`,
+    }))
+    const template = getMentorBulkAssignmentTemplate(
+      name || '',
+      enriched,
+      `${baseUrl}/mentor`,
+    )
+    await sendEmail({ to: email, subject: template.subject, text: template.text, html: template.html })
+  } catch (error) {
+    console.error('[sendMentorBulkAssignmentEmail] failed', { email, error })
+  }
+}
+
 // =============================================================================
 // Mentor change requests (PR 8) — admin notification when an applicant or admin
 // opens a MentorChangeRequest. Mentors are NOT notified (per design decision).

src/server/routers/mentor.ts

@@ -8,8 +8,10 @@ import {
   type PrismaClient,
 } from '@prisma/client'
 import {
+  sendMentorBulkAssignmentEmail,
   sendMentorChangeRequestEmail,
   sendMentorTeamAssignmentEmail,
+  sendTeamMentorIntroductionEmail,
 } from '@/lib/email'
 import {
   getAIMentorSuggestions,
@@ -46,6 +48,104 @@ import {
   verifyMentorUploadToken,
 } from '@/lib/mentor-upload-token'
 
+/**
+ * True if the project is enrolled in a MENTORING round that is still
+ * ROUND_DRAFT. Used to defer mentor- and team-side emails until the round
+ * opens, so admins can stage assignments without sending notifications.
+ * If the project isn't in a MENTORING round at all, returns false
+ * (i.e. send emails normally — there's no round-open event to wait for).
+ */
+async function shouldDeferEmailsForProject(
+  prisma: PrismaClient,
+  projectId: string,
+): Promise<boolean> {
+  const draftRoundEnrollment = await prisma.projectRoundState.findFirst({
+    where: {
+      projectId,
+      round: { roundType: 'MENTORING', status: 'ROUND_DRAFT' },
+    },
+    select: { id: true },
+  })
+  return draftRoundEnrollment !== null
+}
+
+/**
+ * Introduce the project team to ALL active mentors via email IF the project's
+ * MENTORING round is currently ROUND_ACTIVE. Idempotent: only emails mentors
+ * whose assignment row has `teamIntroducedAt: null`. If the round is not yet
+ * active, this is a no-op — the activation step will fire the email instead.
+ * Never throws.
+ */
+async function introduceTeamToMentorsIfRoundOpen(
+  prisma: PrismaClient,
+  projectId: string,
+): Promise<void> {
+  try {
+    const project = await prisma.project.findUnique({
+      where: { id: projectId },
+      select: {
+        id: true,
+        title: true,
+        projectRoundStates: {
+          where: {
+            round: { roundType: 'MENTORING', status: 'ROUND_ACTIVE' },
+          },
+          select: { id: true },
+          take: 1,
+        },
+        mentorAssignments: {
+          where: { droppedAt: null, teamIntroducedAt: null },
+          select: {
+            id: true,
+            mentor: { select: { name: true, email: true } },
+          },
+        },
+        teamMembers: {
+          select: { user: { select: { name: true, email: true } } },
+        },
+        submittedByEmail: true,
+        submittedBy: { select: { name: true } },
+      },
+    })
+    if (!project) return
+    if (project.projectRoundStates.length === 0) return // round not active yet
+    const mentors = project.mentorAssignments
+      .filter((a) => a.mentor?.email)
+      .map((a) => ({ name: a.mentor.name, email: a.mentor.email }))
+    if (mentors.length === 0) return
+
+    const recipients = new Map<string, { name: string | null }>()
+    for (const tm of project.teamMembers) {
+      if (tm.user?.email) {
+        recipients.set(tm.user.email, { name: tm.user.name })
+      }
+    }
+    if (
+      project.submittedByEmail &&
+      !recipients.has(project.submittedByEmail)
+    ) {
+      recipients.set(project.submittedByEmail, {
+        name: project.submittedBy?.name ?? null,
+      })
+    }
+    for (const [email, { name }] of recipients) {
+      await sendTeamMentorIntroductionEmail(
+        email,
+        name,
+        project.title,
+        project.id,
+        mentors,
+      )
+    }
+    await prisma.mentorAssignment.updateMany({
+      where: { id: { in: project.mentorAssignments.map((a) => a.id) } },
+      data: { teamIntroducedAt: new Date() },
+    })
+  } catch (e) {
+    console.error('[introduceTeamToMentorsIfRoundOpen] failed (non-fatal):', e)
+  }
+}
+
 /**
  * Throws TRPCError if the given user is neither the assigned mentor
  * nor a team member of the project linked to the assignment.
@@ -270,6 +370,25 @@ export const mentorRouter = router({
         where: { id: input.projectId },
       })
 
+      // Gate: the project MUST be in a MENTORING round (any status, including
+      // DRAFT, ACTIVE, or CLOSED). We do not allow mentor assignment for
+      // projects that aren't part of a mentoring round — those should be
+      // added to a mentoring round first.
+      const inMentoringRound = await ctx.prisma.projectRoundState.findFirst({
+        where: {
+          projectId: input.projectId,
+          round: { roundType: 'MENTORING' },
+        },
+        select: { id: true },
+      })
+      if (!inMentoringRound) {
+        throw new TRPCError({
+          code: 'BAD_REQUEST',
+          message:
+            'This project is not in a mentoring round. Add it to a mentoring round first, then assign mentors.',
+        })
+      }
+
       // Verify mentor exists
       const mentor = await ctx.prisma.user.findUniqueOrThrow({
         where: { id: input.mentorId },
@@ -346,6 +465,15 @@ export const mentorRouter = router({
         include: { user: { select: { name: true, email: true } } },
       })
 
+      // Defer emails (mentor-side and team-side) while the project's MENTORING
+      // round is still ROUND_DRAFT — `activateRound` coalesces and fires them
+      // when the admin opens the round. In-app notifications still fire so the
+      // staged assignment is visible immediately.
+      const deferThisEmail = await shouldDeferEmailsForProject(
+        ctx.prisma,
+        input.projectId,
+      )
+
       // Notify mentor of new mentee
       await createNotification({
         userId: input.mentorId,
@@ -360,6 +488,7 @@ export const mentorRouter = router({
           teamLeadName: teamLead?.user?.name || 'Team Lead',
           teamLeadEmail: teamLead?.user?.email,
         },
+        skipEmail: deferThisEmail,
       })
 
       // Notify project team of mentor assignment
@@ -374,13 +503,14 @@ export const mentorRouter = router({
           projectName: assignment.project.title,
           mentorName: assignment.mentor.name,
         },
+        skipEmail: deferThisEmail,
       })
 
-      // Send per-team email notification once per assignment row. Idempotency
-      // is enforced via MentorAssignment.notificationSentAt — a fresh row has
-      // it null. If the same mentor is later dropped and re-assigned (new row,
-      // fresh id), a new email is sent — intentional.
-      if (assignment.notificationSentAt == null && assignment.mentor.email) {
+      if (
+        !deferThisEmail &&
+        assignment.notificationSentAt == null &&
+        assignment.mentor.email
+      ) {
         await sendMentorTeamAssignmentEmail(
           assignment.mentor.email,
           assignment.mentor.name,
@@ -414,6 +544,10 @@ export const mentorRouter = router({
         console.error('[Mentor] triggerInProgressOnActivity failed (non-fatal):', e)
       }
 
+      // If the project's MENTORING round is already open, introduce the team
+      // to their mentor(s) by email now. Otherwise the activation hook fires it.
+      await introduceTeamToMentorsIfRoundOpen(ctx.prisma, input.projectId)
+
       return assignment
     }),
 
@@ -531,6 +665,13 @@ export const mentorRouter = router({
         include: { user: { select: { name: true, email: true } } },
       })
 
+      // Defer email notifications if the project's MENTORING round is still
+      // in draft — activateRound will fire coalesced emails at round-open.
+      const deferThisEmail = await shouldDeferEmailsForProject(
+        ctx.prisma,
+        input.projectId,
+      )
+
       // Notify mentor of new mentee
       await createNotification({
         userId: mentorId,
@@ -545,6 +686,7 @@ export const mentorRouter = router({
           teamLeadName: teamLead?.user?.name || 'Team Lead',
           teamLeadEmail: teamLead?.user?.email,
         },
+        skipEmail: deferThisEmail,
       })
 
       // Notify project team of mentor assignment
@@ -559,11 +701,258 @@ export const mentorRouter = router({
           projectName: assignment.project.title,
           mentorName: assignment.mentor.name,
         },
+        skipEmail: deferThisEmail,
       })
 
       return assignment
     }),
 
+  /**
+   * Bulk-assign MANY mentors to MANY projects (cartesian product) in one
+   * call. Skips (mentor, project) pairs where the mentor is already an
+   * active mentor on that project. Each affected mentor receives ONE
+   * coalesced email listing only their newly-assigned projects. Each team
+   * whose project's MENTORING round is already open receives ONE intro
+   * email listing all their active mentors (including any pre-existing).
+   */
+  bulkAssign: adminProcedure
+    .input(
+      z.object({
+        mentorIds: z.array(z.string()).min(1),
+        projectIds: z.array(z.string()).min(1),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const mentors = await ctx.prisma.user.findMany({
+        where: { id: { in: input.mentorIds } },
+        select: { id: true, name: true, email: true, roles: true },
+      })
+      const validMentors = mentors.filter((m) => m.roles.includes('MENTOR'))
+      if (validMentors.length === 0) {
+        throw new TRPCError({
+          code: 'BAD_REQUEST',
+          message: 'None of the selected users have the MENTOR role',
+        })
+      }
+
+      const projects = await ctx.prisma.project.findMany({
+        where: {
+          id: { in: input.projectIds },
+          // Gate: only projects that are in some MENTORING round (any status)
+          projectRoundStates: {
+            some: { round: { roundType: 'MENTORING' } },
+          },
+        },
+        select: {
+          id: true,
+          title: true,
+          mentorAssignments: {
+            where: {
+              mentorId: { in: validMentors.map((m) => m.id) },
+              droppedAt: null,
+            },
+            select: { mentorId: true },
+          },
+        },
+      })
+
+      if (projects.length === 0) {
+        throw new TRPCError({
+          code: 'BAD_REQUEST',
+          message:
+            'None of the selected projects are in a mentoring round. Add them to a mentoring round first.',
+        })
+      }
+
+      const ineligibleCount = input.projectIds.length - projects.length
+
+      // Track per-mentor (for emails) and per-project (for team intros) state.
+      const perMentor = new Map<
+        string,
+        {
+          email: string | null
+          name: string | null
+          assignmentIds: string[]
+          newProjects: { id: string; title: string }[]
+          skippedProjects: { id: string; title: string }[]
+        }
+      >()
+      for (const m of validMentors) {
+        perMentor.set(m.id, {
+          email: m.email ?? null,
+          name: m.name ?? null,
+          assignmentIds: [],
+          newProjects: [],
+          skippedProjects: [],
+        })
+      }
+      const touchedProjectIds = new Set<string>()
+      let totalAssigned = 0
+      let totalSkipped = 0
+
+      // Pre-compute which projects must defer outbound email because their
+      // MENTORING round is still in draft. The in-app notification still
+      // fires; only the parallel notification-system email is suppressed,
+      // exactly like the coalesced mentor email path below. `activateRound`
+      // sends one combined email per mentor + one team intro per project
+      // when the admin opens the round.
+      const draftProjectIds = new Set<string>()
+      for (const project of projects) {
+        if (await shouldDeferEmailsForProject(ctx.prisma, project.id)) {
+          draftProjectIds.add(project.id)
+        }
+      }
+
+      for (const project of projects) {
+        const alreadyOn = new Set(project.mentorAssignments.map((a) => a.mentorId))
+        const deferForThis = draftProjectIds.has(project.id)
+        for (const mentor of validMentors) {
+          const bucket = perMentor.get(mentor.id)!
+          if (alreadyOn.has(mentor.id)) {
+            bucket.skippedProjects.push({ id: project.id, title: project.title })
+            totalSkipped++
+            continue
+          }
+          const created = await ctx.prisma.mentorAssignment.create({
+            data: {
+              projectId: project.id,
+              mentorId: mentor.id,
+              method: 'MANUAL',
+              assignedBy: ctx.user.id,
+            },
+          })
+          bucket.assignmentIds.push(created.id)
+          bucket.newProjects.push({ id: project.id, title: project.title })
+          touchedProjectIds.add(project.id)
+          totalAssigned++
+
+          await createNotification({
+            userId: mentor.id,
+            type: NotificationTypes.MENTEE_ASSIGNED,
+            title: 'New Mentee Assigned',
+            message: `You have been assigned to mentor "${project.title}".`,
+            linkUrl: `/mentor/projects/${project.id}`,
+            linkLabel: 'View Project',
+            priority: 'high',
+            metadata: { projectName: project.title },
+            skipEmail: deferForThis,
+          })
+
+          await notifyProjectTeam(project.id, {
+            type: NotificationTypes.MENTOR_ASSIGNED,
+            title: 'Mentor Assigned',
+            message: `${mentor.name || 'A mentor'} has been assigned to support your project.`,
+            linkUrl: `/team/projects/${project.id}`,
+            linkLabel: 'View Project',
+            priority: 'high',
+            metadata: { projectName: project.title, mentorName: mentor.name },
+            skipEmail: deferForThis,
+          })
+        }
+
+        // Best-effort: mark project IN_PROGRESS in the active MENTORING round
+        if (touchedProjectIds.has(project.id)) {
+          try {
+            const mentoringPrs = await ctx.prisma.projectRoundState.findFirst({
+              where: {
+                projectId: project.id,
+                round: {
+                  roundType: 'MENTORING',
+                  status: { in: ['ROUND_ACTIVE', 'ROUND_CLOSED'] },
+                },
+                state: 'PENDING',
+              },
+              select: { roundId: true },
+            })
+            if (mentoringPrs) {
+              await triggerInProgressOnActivity(
+                project.id,
+                mentoringPrs.roundId,
+                ctx.user.id,
+                ctx.prisma,
+              )
+            }
+          } catch (e) {
+            console.error(
+              '[Mentor.bulkAssign] triggerInProgressOnActivity failed (non-fatal):',
+              e,
+            )
+          }
+        }
+      }
+
+      // `draftProjectIds` was computed before the assignment loop above.
+      // One email per mentor, listing only their NEW projects whose mentoring
+      // round is NOT in draft. If every new project is deferred, no email.
+      for (const bucket of perMentor.values()) {
+        if (!bucket.email) continue
+        const sendableProjects = bucket.newProjects.filter(
+          (p) => !draftProjectIds.has(p.id),
+        )
+        if (sendableProjects.length === 0) continue
+        await sendMentorBulkAssignmentEmail(
+          bucket.email,
+          bucket.name,
+          sendableProjects,
+        )
+        // Only stamp notificationSentAt for the assignments that correspond
+        // to projects we actually emailed about. Draft-deferred ones stay
+        // unstamped so activateRound picks them up.
+        const sendableProjectIds = new Set(sendableProjects.map((p) => p.id))
+        await ctx.prisma.mentorAssignment.updateMany({
+          where: {
+            id: { in: bucket.assignmentIds },
+            projectId: { in: Array.from(sendableProjectIds) },
+          },
+          data: { notificationSentAt: new Date() },
+        })
+      }
+
+      // Team-intro email per touched project (only fires if the round is
+      // already ROUND_ACTIVE — the helper short-circuits otherwise, so draft
+      // projects are naturally deferred to activateRound's intro pass).
+      for (const projectId of touchedProjectIds) {
+        await introduceTeamToMentorsIfRoundOpen(ctx.prisma, projectId)
+      }
+
+      await logAudit({
+        prisma: ctx.prisma,
+        userId: ctx.user.id,
+        action: 'MENTOR_BULK_ASSIGN',
+        entityType: 'BulkAssign',
+        entityId: 'multi',
+        detailsJson: {
+          mentorIds: validMentors.map((m) => m.id),
+          projectIds: input.projectIds,
+          totalAssigned,
+          totalSkipped,
+          perMentor: Array.from(perMentor.entries()).map(([id, b]) => ({
+            mentorId: id,
+            assigned: b.newProjects.length,
+            skipped: b.skippedProjects.length,
+          })),
+        },
+        ipAddress: ctx.ip,
+        userAgent: ctx.userAgent,
+      })
+
+      return {
+        totalAssigned,
+        totalSkipped,
+        ineligibleProjectCount: ineligibleCount,
+        touchedProjectCount: touchedProjectIds.size,
+        perMentor: Array.from(perMentor.entries()).map(([id, b]) => ({
+          mentorId: id,
+          mentorName: b.name,
+          assigned: b.newProjects.length,
+          skipped: b.skippedProjects.length,
+        })),
+        emailsSent: Array.from(perMentor.values()).filter(
+          (b) => b.newProjects.length > 0 && b.email,
+        ).length,
+      }
+    }),
+
   /**
    * Remove mentor assignment.
    *
@@ -714,6 +1103,12 @@ export const mentorRouter = router({
               include: { user: { select: { name: true, email: true } } },
             })
 
+            // Defer emails when the project's MENTORING round is still in draft.
+            const deferThisEmail = await shouldDeferEmailsForProject(
+              ctx.prisma,
+              project.id,
+            )
+
             // Notify mentor
             await createNotification({
               userId: mentorId,
@@ -728,6 +1123,7 @@ export const mentorRouter = router({
                 teamLeadName: teamLead?.user?.name || 'Team Lead',
                 teamLeadEmail: teamLead?.user?.email,
               },
+              skipEmail: deferThisEmail,
             })
 
             // Notify project team
@@ -742,6 +1138,7 @@ export const mentorRouter = router({
                 projectName: assignment.project.title,
                 mentorName: assignment.mentor.name,
               },
+              skipEmail: deferThisEmail,
             })
 
             assigned++
@@ -795,7 +1192,7 @@ export const mentorRouter = router({
     .mutation(async ({ ctx, input }) => {
       const round = await ctx.prisma.round.findUniqueOrThrow({
         where: { id: input.roundId },
-        select: { id: true, roundType: true, configJson: true },
+        select: { id: true, roundType: true, configJson: true, status: true },
       })
       if (round.roundType !== 'MENTORING') {
         throw new TRPCError({
@@ -818,7 +1215,7 @@ export const mentorRouter = router({
         where: {
           roundId: input.roundId,
           project: {
-            mentorAssignments: { none: {} },
+            mentorAssignments: { none: { droppedAt: null } },
             // Only assign mentors to projects whose team has confirmed they will
             // attend the grand finale. This skips PENDING/DECLINED/EXPIRED/SUPERSEDED
             // confirmations and any project without a confirmation row at all.
@@ -842,6 +1239,23 @@ export const mentorRouter = router({
       let assigned = 0
       let unassignable = 0
 
+      // Defer outbound emails when the round is still in draft — same gate
+      // used by mentor.assign/bulkAssign. In-app notifications still fire so
+      // the staged assignment is visible to the mentor + team immediately.
+      const deferEmailsForRound = round.status === 'ROUND_DRAFT'
+
+      // Coalesce per-mentor so we send ONE email per mentor at the end of the
+      // batch, even when the algorithm assigns the same mentor to several teams.
+      const perMentor = new Map<
+        string,
+        {
+          email: string | null
+          name: string | null
+          assignmentIds: string[]
+          projects: { id: string; title: string }[]
+        }
+      >()
+
       for (const { project } of projectStates) {
         try {
           let mentorId: string | null = null
@@ -883,7 +1297,7 @@ export const mentorRouter = router({
               aiReasoning,
             },
             include: {
-              mentor: { select: { id: true, name: true } },
+              mentor: { select: { id: true, name: true, email: true } },
               project: { select: { title: true } },
             },
           })
@@ -906,6 +1320,7 @@ export const mentorRouter = router({
               teamLeadName: teamLead?.user?.name || 'Team Lead',
               teamLeadEmail: teamLead?.user?.email,
             },
+            skipEmail: deferEmailsForRound,
           })
 
           await notifyProjectTeam(project.id, {
@@ -919,8 +1334,20 @@ export const mentorRouter = router({
               projectName: assignment.project.title,
               mentorName: assignment.mentor.name,
             },
+            skipEmail: deferEmailsForRound,
           })
 
+          // Accumulate for the coalesced email
+          const bucket = perMentor.get(mentorId) ?? {
+            email: assignment.mentor.email ?? null,
+            name: assignment.mentor.name ?? null,
+            assignmentIds: [],
+            projects: [],
+          }
+          bucket.assignmentIds.push(assignment.id)
+          bucket.projects.push({ id: project.id, title: assignment.project.title })
+          perMentor.set(mentorId, bucket)
+
           assigned++
         } catch (err) {
           console.error(
@@ -932,6 +1359,49 @@ export const mentorRouter = router({
         }
       }
 
+      // Defer all emails when the round is still ROUND_DRAFT — activateRound
+      // will coalesce and send them when the admin opens the round. Stamp
+      // notificationSentAt only for assignments we actually email about, so
+      // activateRound's `notificationSentAt IS NULL` filter catches the rest.
+      const roundStatus = await ctx.prisma.round.findUnique({
+        where: { id: input.roundId },
+        select: { status: true },
+      })
+      const isRoundLive = roundStatus?.status === 'ROUND_ACTIVE'
+
+      if (isRoundLive) {
+        for (const bucket of perMentor.values()) {
+          if (!bucket.email || bucket.projects.length === 0) continue
+          await sendMentorBulkAssignmentEmail(
+            bucket.email,
+            bucket.name,
+            bucket.projects,
+          )
+          try {
+            await ctx.prisma.mentorAssignment.updateMany({
+              where: { id: { in: bucket.assignmentIds } },
+              data: { notificationSentAt: new Date() },
+            })
+          } catch (e) {
+            console.error(
+              '[Mentor.autoAssignBulkForRound] failed to stamp notificationSentAt (non-fatal):',
+              e,
+            )
+          }
+        }
+
+        const introducedProjects = new Set<string>()
+        for (const bucket of perMentor.values()) {
+          for (const p of bucket.projects) {
+            if (introducedProjects.has(p.id)) continue
+            introducedProjects.add(p.id)
+            await introduceTeamToMentorsIfRoundOpen(ctx.prisma, p.id)
+          }
+        }
+      }
+      // If the round is still ROUND_DRAFT, no emails fire here — the assignments
+      // remain unstamped and activateRound will batch-send when the round opens.
+
       const skipped = await ctx.prisma.projectRoundState.count({
         where: {
           roundId: input.roundId,

src/server/routers/round.ts

@@ -227,21 +227,169 @@ export const roundRouter = router({
         where: { id: input.roundId },
         select: { roundType: true, configJson: true },
       })
-      if (round.roundType !== 'MENTORING') return { count: 0 }
+      if (round.roundType !== 'MENTORING') {
+        return { count: 0, eligibleTotal: 0, mentorPoolSize: 0 }
+      }
       const config = (round.configJson ?? {}) as Record<string, unknown>
       const eligibility = (config.eligibility as string) ?? 'requested_only'
-      if (eligibility === 'admin_selected') return { count: 0 }
+      if (eligibility === 'admin_selected') {
+        return { count: 0, eligibleTotal: 0, mentorPoolSize: 0 }
+      }
 
-      const count = await ctx.prisma.projectRoundState.count({
+      const eligibilityWhere =
+        eligibility === 'requested_only' ? { wantsMentorship: true } : {}
+
+      // Mirror autoAssignBulkForRound's filter exactly so the toolbar count
+      // matches what the auto-fill button will actually process.
+      const autoFillWhere = {
+        mentorAssignments: { none: { droppedAt: null } },
+        finalistConfirmation: { status: 'CONFIRMED' as const },
+        ...eligibilityWhere,
+      }
+      const [count, eligibleTotal, mentorPoolSize] = await Promise.all([
+        ctx.prisma.projectRoundState.count({
+          where: { roundId: input.roundId, project: autoFillWhere },
+        }),
+        ctx.prisma.projectRoundState.count({
           where: {
             roundId: input.roundId,
             project: {
-            mentorAssignments: { none: {} },
-            ...(eligibility === 'requested_only' ? { wantsMentorship: true } : {}),
+              finalistConfirmation: { status: 'CONFIRMED' as const },
+              ...eligibilityWhere,
             },
           },
+        }),
+        ctx.prisma.user.count({
+          where: { roles: { has: 'MENTOR' }, status: { not: 'SUSPENDED' } },
+        }),
+      ])
+      return { count, eligibleTotal, mentorPoolSize }
+    }),
+
+  /**
+   * For a MENTORING round, find the immediately-prior round in the same
+   * competition and report how many of its PASSED projects are not yet
+   * present in this round. Drives the "Import from prior round" CTA so
+   * admins don't have to manually pick projects via the From-Round modal.
+   */
+  getMentoringImportCandidates: adminProcedure
+    .input(z.object({ roundId: z.string() }))
+    .query(async ({ ctx, input }) => {
+      const round = await ctx.prisma.round.findUniqueOrThrow({
+        where: { id: input.roundId },
+        select: { roundType: true, competitionId: true, sortOrder: true },
       })
-      return { count }
+      if (round.roundType !== 'MENTORING') {
+        return { priorRound: null, pendingCount: 0 }
+      }
+      const prior = await ctx.prisma.round.findFirst({
+        where: {
+          competitionId: round.competitionId,
+          sortOrder: { lt: round.sortOrder },
+        },
+        orderBy: { sortOrder: 'desc' },
+        select: { id: true, name: true, status: true },
+      })
+      if (!prior) return { priorRound: null, pendingCount: 0 }
+      if (prior.status !== 'ROUND_ACTIVE' && prior.status !== 'ROUND_CLOSED') {
+        return {
+          priorRound: { id: prior.id, name: prior.name, status: prior.status },
+          pendingCount: 0,
+        }
+      }
+      const existingInTarget = await ctx.prisma.projectRoundState.findMany({
+        where: { roundId: input.roundId },
+        select: { projectId: true },
+      })
+      const existingIds = new Set(existingInTarget.map((s) => s.projectId))
+      const passedInPrior = await ctx.prisma.projectRoundState.findMany({
+        where: { roundId: prior.id, state: 'PASSED' },
+        select: { projectId: true },
+      })
+      const pendingCount = passedInPrior.filter(
+        (s) => !existingIds.has(s.projectId),
+      ).length
+      return {
+        priorRound: { id: prior.id, name: prior.name, status: prior.status },
+        pendingCount,
+      }
+    }),
+
+  /**
+   * List projects in a MENTORING round with their (multi-)mentor assignments.
+   * Drives the per-team assignment table on the round Projects tab so admins
+   * can see who is assigned to whom and add/swap mentors per project.
+   */
+  listMentoringProjects: adminProcedure
+    .input(z.object({ roundId: z.string() }))
+    .query(async ({ ctx, input }) => {
+      const round = await ctx.prisma.round.findUniqueOrThrow({
+        where: { id: input.roundId },
+        select: { roundType: true, configJson: true },
+      })
+      if (round.roundType !== 'MENTORING') return { projects: [] }
+
+      const config = (round.configJson ?? {}) as Record<string, unknown>
+      const eligibility = (config.eligibility as string) ?? 'requested_only'
+
+      const states = await ctx.prisma.projectRoundState.findMany({
+        where: { roundId: input.roundId },
+        select: {
+          state: true,
+          project: {
+            select: {
+              id: true,
+              title: true,
+              teamName: true,
+              country: true,
+              wantsMentorship: true,
+              competitionCategory: true,
+              finalistConfirmation: { select: { status: true } },
+              mentorAssignments: {
+                where: { droppedAt: null },
+                select: {
+                  id: true,
+                  method: true,
+                  assignedAt: true,
+                  mentor: { select: { id: true, name: true, email: true } },
+                },
+                orderBy: { assignedAt: 'asc' },
+              },
+            },
+          },
+        },
+        orderBy: [{ project: { title: 'asc' } }],
+      })
+
+      return {
+        eligibility,
+        projects: states.map((s) => {
+          const isEligible =
+            eligibility === 'all_in_round' ||
+            eligibility === 'admin_selected' ||
+            s.project.wantsMentorship
+          return {
+            id: s.project.id,
+            title: s.project.title,
+            teamName: s.project.teamName,
+            country: s.project.country,
+            competitionCategory: s.project.competitionCategory,
+            wantsMentorship: s.project.wantsMentorship,
+            finalistConfirmationStatus:
+              s.project.finalistConfirmation?.status ?? null,
+            isEligible,
+            state: s.state,
+            mentors: s.project.mentorAssignments.map((a) => ({
+              assignmentId: a.id,
+              method: a.method,
+              assignedAt: a.assignedAt,
+              id: a.mentor.id,
+              name: a.mentor.name,
+              email: a.mentor.email,
+            })),
+          }
+        }),
+      }
     }),
 
   /**

src/server/services/in-app-notification.ts

@@ -169,6 +169,14 @@ interface CreateNotificationParams {
   metadata?: Record<string, unknown>
   groupKey?: string
   expiresAt?: Date
+  /**
+   * When true, the in-app notification still fires but the parallel email
+   * send (via NotificationEmailSetting) is suppressed. Callers use this when
+   * the email belongs to a coalesced/deferred flow that will fire later
+   * (e.g. mentor assignments staged while a MENTORING round is ROUND_DRAFT —
+   * the round-open hook sends a single combined email instead).
+   */
+  skipEmail?: boolean
 }
 
 /**
@@ -189,6 +197,7 @@ export async function createNotification(
     metadata,
     groupKey,
     expiresAt,
+    skipEmail,
   } = params
 
   // Determine icon and priority if not provided
@@ -241,8 +250,11 @@ export async function createNotification(
     },
   })
 
-  // Check if we should also send an email
+  // Check if we should also send an email (suppressed when the caller is
+  // deferring the email to a coalesced flow).
+  if (!skipEmail) {
     await maybeSendEmail(userId, type, title, message, linkUrl, metadata)
+  }
 }
 
 /**
@@ -258,6 +270,8 @@ export async function createBulkNotifications(params: {
   icon?: string
   priority?: NotificationPriority
   metadata?: Record<string, unknown>
+  /** See {@link CreateNotificationParams.skipEmail}. */
+  skipEmail?: boolean
 }): Promise<void> {
   const {
     userIds,
@@ -269,6 +283,7 @@ export async function createBulkNotifications(params: {
     icon,
     priority,
     metadata,
+    skipEmail,
   } = params
 
   const finalIcon = icon || NotificationIcons[type] || 'Bell'
@@ -289,6 +304,8 @@ export async function createBulkNotifications(params: {
     })),
   })
 
+  if (skipEmail) return
+
   // Check email settings once, then send emails only if enabled
   const emailSetting = await prisma.notificationEmailSetting.findUnique({
     where: { notificationType: type },

src/server/services/round-engine.ts

@@ -16,6 +16,10 @@ import { logAudit } from '@/server/utils/audit'
 import { safeValidateRoundConfig } from '@/types/competition-configs'
 import { expireIntentsForRound } from './assignment-intent'
 import { processRoundClose } from './round-finalization'
+import {
+  sendMentorBulkAssignmentEmail,
+  sendTeamMentorIntroductionEmail,
+} from '@/lib/email'
 
 // ─── Types ──────────────────────────────────────────────────────────────────
 
@@ -211,6 +215,150 @@ export async function activateRound(
       } catch (mentoringError) {
         console.error('[RoundEngine] Mentoring pass-through failed (non-fatal):', mentoringError)
       }
+
+      // Mentor-side coalesced emails on round open. Picks up every assignment
+      // for projects in this round whose notificationSentAt is null (i.e.
+      // assignments made while the round was still in draft), groups by
+      // mentor, and sends a single combined email per mentor listing all
+      // their projects in this round.
+      try {
+        const pendingAssignments = await prisma.mentorAssignment.findMany({
+          where: {
+            droppedAt: null,
+            notificationSentAt: null,
+            project: { projectRoundStates: { some: { roundId } } },
+          },
+          select: {
+            id: true,
+            mentorId: true,
+            mentor: { select: { name: true, email: true } },
+            project: { select: { id: true, title: true } },
+          },
+        })
+        const perMentor = new Map<
+          string,
+          {
+            email: string | null
+            name: string | null
+            assignmentIds: string[]
+            projects: { id: string; title: string }[]
+          }
+        >()
+        for (const a of pendingAssignments) {
+          if (!a.mentor?.email) continue
+          const bucket = perMentor.get(a.mentorId) ?? {
+            email: a.mentor.email,
+            name: a.mentor.name,
+            assignmentIds: [],
+            projects: [],
+          }
+          bucket.assignmentIds.push(a.id)
+          bucket.projects.push({ id: a.project.id, title: a.project.title })
+          perMentor.set(a.mentorId, bucket)
+        }
+        for (const bucket of perMentor.values()) {
+          if (bucket.projects.length === 0 || !bucket.email) continue
+          await sendMentorBulkAssignmentEmail(
+            bucket.email,
+            bucket.name,
+            bucket.projects,
+          )
+          await prisma.mentorAssignment.updateMany({
+            where: { id: { in: bucket.assignmentIds } },
+            data: { notificationSentAt: new Date() },
+          })
+        }
+        if (perMentor.size > 0) {
+          console.log(
+            `[RoundEngine] MENTORING round open: notified ${perMentor.size} mentor(s) about their assignments`,
+          )
+        }
+      } catch (mentorEmailError) {
+        console.error(
+          '[RoundEngine] Mentor-side coalesced notification failed (non-fatal):',
+          mentorEmailError,
+        )
+      }
+
+      // Introduce teams to their mentors via email when the round opens.
+      // Idempotent via MentorAssignment.teamIntroducedAt — separate from the
+      // mentor-side notificationSentAt so the team email fires even when the
+      // mentor was assigned (and notified) before the round opened.
+      try {
+        const projectsToIntroduce = await prisma.project.findMany({
+          where: {
+            projectRoundStates: { some: { roundId } },
+            mentorAssignments: {
+              some: { droppedAt: null, teamIntroducedAt: null },
+            },
+          },
+          select: {
+            id: true,
+            title: true,
+            mentorAssignments: {
+              where: { droppedAt: null },
+              select: {
+                id: true,
+                teamIntroducedAt: true,
+                mentor: { select: { name: true, email: true } },
+              },
+            },
+            teamMembers: {
+              select: { user: { select: { name: true, email: true } } },
+            },
+            submittedByEmail: true,
+            submittedBy: { select: { name: true } },
+          },
+        })
+        for (const p of projectsToIntroduce) {
+          const mentors = p.mentorAssignments
+            .filter((a) => a.mentor?.email)
+            .map((a) => ({
+              name: a.mentor.name,
+              email: a.mentor.email,
+            }))
+          if (mentors.length === 0) continue
+
+          // Build a unique recipient set: team-member users with emails,
+          // plus the original submitter (in case they're not on the team yet).
+          const recipients = new Map<string, { name: string | null }>()
+          for (const tm of p.teamMembers) {
+            if (tm.user?.email) {
+              recipients.set(tm.user.email, { name: tm.user.name })
+            }
+          }
+          if (
+            p.submittedByEmail &&
+            !recipients.has(p.submittedByEmail)
+          ) {
+            recipients.set(p.submittedByEmail, {
+              name: p.submittedBy?.name ?? null,
+            })
+          }
+
+          for (const [email, { name }] of recipients) {
+            await sendTeamMentorIntroductionEmail(email, name, p.title, p.id, mentors)
+          }
+
+          // Stamp every mentor-assignment row so re-activation doesn't re-send.
+          const idsToStamp = p.mentorAssignments
+            .filter((a) => a.teamIntroducedAt == null)
+            .map((a) => a.id)
+          if (idsToStamp.length > 0) {
+            await prisma.mentorAssignment.updateMany({
+              where: { id: { in: idsToStamp } },
+              data: { teamIntroducedAt: new Date() },
+            })
+          }
+        }
+        if (projectsToIntroduce.length > 0) {
+          console.log(
+            `[RoundEngine] MENTORING round open: introduced mentors for ${projectsToIntroduce.length} project(s)`,
+          )
+        }
+      } catch (introError) {
+        console.error('[RoundEngine] Team-mentor introduction failed (non-fatal):', introError)
+      }
     }
 
     return {

tests/unit/mentor-email-deferral.test.ts

@@ -0,0 +1,228 @@
+/**
+ * Regression: mentor-assignment emails must be deferred while the
+ * project's MENTORING round is still ROUND_DRAFT. The earlier fix only
+ * deferred the explicit `sendMentorBulkAssignmentEmail` path; the parallel
+ * in-app-notification → email path (MENTEE_ASSIGNED, MENTOR_ASSIGNED) kept
+ * firing immediately, causing duplicate sends both at assign-time AND
+ * again when activateRound coalesced the same assignments. Verified
+ * against prod incident 2026-05-26 (Camille Lopez received 9 emails).
+ *
+ * These tests assert that:
+ *   - in DRAFT: in-app notifications still create rows, but the styled
+ *     notification email is NOT sent;
+ *   - in ACTIVE: the styled notification email IS sent (legacy behaviour
+ *     preserved when the round is open).
+ */
+
+import { afterAll, beforeEach, describe, expect, it, vi } from 'vitest'
+import { prisma, createCaller } from '../setup'
+import {
+  createTestUser,
+  createTestProgram,
+  createTestProject,
+  cleanupTestData,
+  uid,
+} from '../helpers'
+import { mentorRouter } from '../../src/server/routers/mentor'
+import type { UserRole } from '@prisma/client'
+
+vi.mock('@/lib/email', async () => {
+  const actual = await vi.importActual<typeof import('@/lib/email')>('@/lib/email')
+  return {
+    ...actual,
+    sendStyledNotificationEmail: vi.fn(async () => undefined),
+    sendMentorTeamAssignmentEmail: vi.fn(async () => undefined),
+    sendMentorBulkAssignmentEmail: vi.fn(async () => undefined),
+    sendTeamMentorIntroductionEmail: vi.fn(async () => undefined),
+  }
+})
+
+const email = await import('@/lib/email')
+const sendStyledMock = email.sendStyledNotificationEmail as ReturnType<typeof vi.fn>
+const sendMentorBulkMock = email.sendMentorBulkAssignmentEmail as ReturnType<typeof vi.fn>
+const sendTeamIntroMock = email.sendTeamMentorIntroductionEmail as ReturnType<typeof vi.fn>
+
+async function makeMentor(): Promise<{ id: string; email: string }> {
+  const id = uid('mentor')
+  const u = await prisma.user.create({
+    data: {
+      id,
+      email: `${id}@test.local`,
+      name: `Mentor ${id}`,
+      role: 'MENTOR' as UserRole,
+      roles: ['MENTOR'] as UserRole[],
+      status: 'ACTIVE',
+      // Email path requires the user to opt into emails. Default for new test
+      // users is EMAIL so styled-email sends fire when the gate is open.
+      notificationPreference: 'EMAIL',
+    },
+  })
+  return { id: u.id, email: u.email }
+}
+
+async function makeTeamMember(projectId: string): Promise<string> {
+  const id = uid('teamuser')
+  const u = await prisma.user.create({
+    data: {
+      id,
+      email: `${id}@test.local`,
+      name: `Team ${id}`,
+      role: 'APPLICANT' as UserRole,
+      roles: ['APPLICANT'] as UserRole[],
+      status: 'ACTIVE',
+      notificationPreference: 'EMAIL',
+    },
+  })
+  await prisma.teamMember.create({
+    data: { projectId, userId: u.id, role: 'MEMBER' },
+  })
+  return u.id
+}
+
+async function attachToMentoringRound(
+  programId: string,
+  projectId: string,
+  status: 'ROUND_DRAFT' | 'ROUND_ACTIVE',
+): Promise<string> {
+  const slug = uid()
+  const competition = await prisma.competition.create({
+    data: {
+      name: `Comp ${slug}`,
+      slug: `comp-${slug}`,
+      programId,
+      status: 'ACTIVE',
+    },
+  })
+  const round = await prisma.round.create({
+    data: {
+      name: `Mentoring ${slug}`,
+      slug: `mentoring-${slug}`,
+      roundType: 'MENTORING',
+      sortOrder: 1,
+      status,
+      competitionId: competition.id,
+    },
+  })
+  await prisma.projectRoundState.create({
+    data: { roundId: round.id, projectId },
+  })
+  return round.id
+}
+
+describe('mentor-assignment email deferral (regression for 2026-05-26 duplicate-email incident)', () => {
+  const programIds: string[] = []
+  const userIds: string[] = []
+
+  beforeEach(() => {
+    sendStyledMock.mockClear()
+    sendMentorBulkMock.mockClear()
+    sendTeamIntroMock.mockClear()
+  })
+
+  afterAll(async () => {
+    for (const programId of programIds) {
+      await prisma.mentorAssignment.deleteMany({ where: { project: { programId } } })
+      await prisma.teamMember.deleteMany({ where: { project: { programId } } })
+      await cleanupTestData(programId, [])
+    }
+    if (userIds.length > 0) {
+      await prisma.user.deleteMany({ where: { id: { in: userIds } } })
+    }
+  })
+
+  it('mentor.assign in DRAFT round creates in-app notif rows but sends ZERO emails', async () => {
+    const admin = await createTestUser('SUPER_ADMIN')
+    userIds.push(admin.id)
+    const program = await createTestProgram({ name: `defer-draft-${uid()}` })
+    programIds.push(program.id)
+    const project = await createTestProject(program.id, { title: 'Draft Project' })
+    await attachToMentoringRound(program.id, project.id, 'ROUND_DRAFT')
+
+    const mentor = await makeMentor()
+    userIds.push(mentor.id)
+    const teamUser = await makeTeamMember(project.id)
+    userIds.push(teamUser)
+
+    const caller = createCaller(mentorRouter, {
+      id: admin.id,
+      email: admin.email,
+      role: 'SUPER_ADMIN',
+    })
+    await caller.assign({ projectId: project.id, mentorId: mentor.id })
+
+    expect(sendStyledMock).not.toHaveBeenCalled()
+    expect(sendMentorBulkMock).not.toHaveBeenCalled()
+    expect(sendTeamIntroMock).not.toHaveBeenCalled()
+
+    // In-app notification rows still fire so admin + mentor see staged state.
+    const mentorNotifs = await prisma.inAppNotification.findMany({
+      where: { userId: mentor.id, type: 'MENTEE_ASSIGNED' },
+    })
+    expect(mentorNotifs.length).toBe(1)
+    const teamNotifs = await prisma.inAppNotification.findMany({
+      where: { userId: teamUser, type: 'MENTOR_ASSIGNED' },
+    })
+    expect(teamNotifs.length).toBe(1)
+  })
+
+  it('mentor.assign in ACTIVE round still sends the per-assignment emails (legacy behaviour preserved)', async () => {
+    const admin = await createTestUser('SUPER_ADMIN')
+    userIds.push(admin.id)
+    const program = await createTestProgram({ name: `defer-active-${uid()}` })
+    programIds.push(program.id)
+    const project = await createTestProject(program.id, { title: 'Active Project' })
+    await attachToMentoringRound(program.id, project.id, 'ROUND_ACTIVE')
+
+    const mentor = await makeMentor()
+    userIds.push(mentor.id)
+    const teamUser = await makeTeamMember(project.id)
+    userIds.push(teamUser)
+
+    const caller = createCaller(mentorRouter, {
+      id: admin.id,
+      email: admin.email,
+      role: 'SUPER_ADMIN',
+    })
+    await caller.assign({ projectId: project.id, mentorId: mentor.id })
+
+    // Either styled notif email OR the explicit team-intro email is allowed
+    // to fire here — point is: at least one outbound email happens when the
+    // round is open. The DRAFT test above is the one that must stay at zero.
+    const sentCount =
+      sendStyledMock.mock.calls.length + sendTeamIntroMock.mock.calls.length
+    expect(sentCount).toBeGreaterThan(0)
+  })
+
+  it('mentor.bulkAssign in DRAFT round sends ZERO emails across multiple projects', async () => {
+    const admin = await createTestUser('SUPER_ADMIN')
+    userIds.push(admin.id)
+    const program = await createTestProgram({ name: `defer-bulk-${uid()}` })
+    programIds.push(program.id)
+    const p1 = await createTestProject(program.id, { title: 'BulkDraft 1' })
+    const p2 = await createTestProject(program.id, { title: 'BulkDraft 2' })
+    const p3 = await createTestProject(program.id, { title: 'BulkDraft 3' })
+    await attachToMentoringRound(program.id, p1.id, 'ROUND_DRAFT')
+    await attachToMentoringRound(program.id, p2.id, 'ROUND_DRAFT')
+    await attachToMentoringRound(program.id, p3.id, 'ROUND_DRAFT')
+
+    const mentor = await makeMentor()
+    userIds.push(mentor.id)
+    userIds.push(await makeTeamMember(p1.id))
+    userIds.push(await makeTeamMember(p2.id))
+    userIds.push(await makeTeamMember(p3.id))
+
+    const caller = createCaller(mentorRouter, {
+      id: admin.id,
+      email: admin.email,
+      role: 'SUPER_ADMIN',
+    })
+    await caller.bulkAssign({
+      mentorIds: [mentor.id],
+      projectIds: [p1.id, p2.id, p3.id],
+    })
+
+    expect(sendStyledMock).not.toHaveBeenCalled()
+    expect(sendMentorBulkMock).not.toHaveBeenCalled()
+    expect(sendTeamIntroMock).not.toHaveBeenCalled()
+  })
+})

tests/unit/multi-mentor-assignment.test.ts

@@ -42,6 +42,37 @@ async function createUserWithRoles(
   })
 }
 
+/**
+ * mentor.assign and mentor.bulkAssign now require the project to be enrolled
+ * in some MENTORING round. This helper sets up the minimum: one competition
+ * + one MENTORING round + one ProjectRoundState linking the project.
+ */
+async function attachToMentoringRound(programId: string, projectId: string) {
+  const compSlug = `comp-${uid()}`
+  const competition = await prisma.competition.create({
+    data: {
+      name: `Comp ${compSlug}`,
+      slug: compSlug,
+      programId,
+      status: 'ACTIVE',
+    },
+  })
+  const round = await prisma.round.create({
+    data: {
+      name: `Mentoring ${uid()}`,
+      slug: `mentoring-${uid()}`,
+      roundType: 'MENTORING',
+      sortOrder: 1,
+      status: 'ROUND_ACTIVE',
+      competitionId: competition.id,
+    },
+  })
+  await prisma.projectRoundState.create({
+    data: { roundId: round.id, projectId },
+  })
+  return { competitionId: competition.id, roundId: round.id }
+}
+
 describe('mentor.assign — stacking + per-team email idempotency', () => {
   const programIds: string[] = []
   const userIds: string[] = []
@@ -62,6 +93,7 @@ describe('mentor.assign — stacking + per-team email idempotency', () => {
     const program = await createTestProgram({ name: `assign-stack-${uid()}` })
     programIds.push(program.id)
     const project = await createTestProject(program.id, { title: 'Stacking Project' })
+    await attachToMentoringRound(program.id, project.id)
 
     const m1 = await createUserWithRoles('MENTOR', ['MENTOR'], { name: 'M1' })
     const m2 = await createUserWithRoles('MENTOR', ['MENTOR'], { name: 'M2' })
@@ -93,6 +125,7 @@ describe('mentor.assign — stacking + per-team email idempotency', () => {
     const program = await createTestProgram({ name: `assign-dup-${uid()}` })
     programIds.push(program.id)
     const project = await createTestProject(program.id, { title: 'Dup Project' })
+    await attachToMentoringRound(program.id, project.id)
     const mentor = await createUserWithRoles('MENTOR', ['MENTOR'])
     userIds.push(mentor.id)
 
@@ -114,7 +147,9 @@ describe('mentor.assign — stacking + per-team email idempotency', () => {
     const program = await createTestProgram({ name: `assign-email-${uid()}` })
     programIds.push(program.id)
     const project1 = await createTestProject(program.id, { title: 'Project Alpha' })
+    await attachToMentoringRound(program.id, project1.id)
     const project2 = await createTestProject(program.id, { title: 'Project Beta' })
+    await attachToMentoringRound(program.id, project2.id)
     const mentor = await createUserWithRoles('MENTOR', ['MENTOR'])
     userIds.push(mentor.id)
 
@@ -144,6 +179,7 @@ describe('mentor.assign — stacking + per-team email idempotency', () => {
     const program = await createTestProgram({ name: `assign-comentor-${uid()}` })
     programIds.push(program.id)
     const project = await createTestProject(program.id, { title: 'Co-mentor Project' })
+    await attachToMentoringRound(program.id, project.id)
     const m1 = await createUserWithRoles('MENTOR', ['MENTOR'], { name: 'Co-1' })
     const m2 = await createUserWithRoles('MENTOR', ['MENTOR'], { name: 'Co-2' })
     userIds.push(m1.id, m2.id)
@@ -169,6 +205,7 @@ describe('mentor.assign — stacking + per-team email idempotency', () => {
     const program = await createTestProgram({ name: `assign-redrop-${uid()}` })
     programIds.push(program.id)
     const project = await createTestProject(program.id, { title: 'Re-assign Project' })
+    await attachToMentoringRound(program.id, project.id)
     const mentor = await createUserWithRoles('MENTOR', ['MENTOR'])
     userIds.push(mentor.id)