feat(02-03): add Advance Top N dialog + batch-reject to RankingDashboard

- Add pendingReorderCount ref + onMutate/onSettled to saveReorderMutation (DASH-07)
- Add advanceMutation (trpc.round.advanceProjects) with getProjectStates invalidation
- Add batchRejectMutation (trpc.roundEngine.batchTransition) using .length per MEMORY.md
- Add handleAdvance: advances top N per category, optionally batch-rejects the rest
- Add Advance Top N button in header (disabled when saveReorderMutation.isPending)
- Add Dialog with per-category N inputs, batch-reject checkbox, and count preview
- Import Dialog, Input, Label, Trophy from shadcn/lucide

src/components/admin/round/ranking-dashboard.tsx

@@ -33,11 +33,22 @@ import {
   SheetTitle,
   SheetDescription,
 } from '@/components/ui/sheet'
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from '@/components/ui/dialog'
+import { Input } from '@/components/ui/input'
+import { Label } from '@/components/ui/label'
 import {
   GripVertical,
   BarChart3,
   Loader2,
   RefreshCw,
+  Trophy,
 } from 'lucide-react'
 import type { RankedProjectEntry } from '@/server/services/ai-ranking'
 
@@ -158,6 +169,13 @@ export function RankingDashboard({ competitionId: _competitionId, roundId }: Ran
     BUSINESS_CONCEPT: [],
   })
   const initialized = useRef(false)
+  const pendingReorderCount = useRef(0)
+
+  // ─── Advance dialog state ─────────────────────────────────────────────────
+  const [advanceDialogOpen, setAdvanceDialogOpen] = useState(false)
+  const [topNStartup, setTopNStartup] = useState(3)
+  const [topNConceptual, setTopNConceptual] = useState(3)
+  const [includeReject, setIncludeReject] = useState(false)
 
   // ─── Sensors ──────────────────────────────────────────────────────────────
   const sensors = useSensors(
@@ -188,6 +206,8 @@ export function RankingDashboard({ competitionId: _competitionId, roundId }: Ran
   const utils = trpc.useUtils()
 
   const saveReorderMutation = trpc.ranking.saveReorder.useMutation({
+    onMutate: () => { pendingReorderCount.current++ },
+    onSettled: () => { pendingReorderCount.current-- },
     onError: (err) => toast.error(`Failed to save order: ${err.message}`),
     // Do NOT invalidate getSnapshot — would reset localOrder
   })
@@ -201,6 +221,28 @@ export function RankingDashboard({ competitionId: _competitionId, roundId }: Ran
     onError: (err) => toast.error(err.message),
   })
 
+  const advanceMutation = trpc.round.advanceProjects.useMutation({
+    onSuccess: (data) => {
+      toast.success(`Advanced ${data.advancedCount} project(s) to ${data.targetRoundName}`)
+      void utils.roundEngine.getProjectStates.invalidate({ roundId })
+      setAdvanceDialogOpen(false)
+    },
+    onError: (err) => toast.error(err.message),
+  })
+
+  const batchRejectMutation = trpc.roundEngine.batchTransition.useMutation({
+    onSuccess: (data) => {
+      // MEMORY.md: use .length, not direct value comparison
+      toast.success(`Rejected ${data.succeeded.length} project(s)`)
+      if (data.failed.length > 0) {
+        toast.warning(`${data.failed.length} project(s) could not be rejected`)
+      }
+      void utils.roundEngine.getProjectStates.invalidate({ roundId })
+      setAdvanceDialogOpen(false)
+    },
+    onError: (err) => toast.error(err.message),
+  })
+
   // ─── rankingMap (O(1) lookup) ──────────────────────────────────────────────
   const rankingMap = useMemo(() => {
     const map = new Map<string, RankedProjectEntry>()
@@ -244,6 +286,26 @@ export function RankingDashboard({ competitionId: _competitionId, roundId }: Ran
     })
   }
 
+  // ─── handleAdvance ────────────────────────────────────────────────────────
+  function handleAdvance() {
+    const advanceIds = [
+      ...localOrder.STARTUP.slice(0, topNStartup),
+      ...localOrder.BUSINESS_CONCEPT.slice(0, topNConceptual),
+    ]
+    const advanceSet = new Set(advanceIds)
+
+    advanceMutation.mutate({ roundId, projectIds: advanceIds })
+
+    if (includeReject) {
+      const rejectIds = [...localOrder.STARTUP, ...localOrder.BUSINESS_CONCEPT].filter(
+        (id) => !advanceSet.has(id),
+      )
+      if (rejectIds.length > 0) {
+        batchRejectMutation.mutate({ projectIds: rejectIds, roundId, newState: 'REJECTED' })
+      }
+    }
+  }
+
   // ─── Loading state ────────────────────────────────────────────────────────
   if (snapshotsLoading || snapshotLoading) {
     return (
@@ -318,12 +380,12 @@ export function RankingDashboard({ competitionId: _competitionId, roundId }: Ran
                 </CardDescription>
               )}
             </div>
+            <div className="flex items-center gap-2 flex-shrink-0">
               <Button
                 size="sm"
                 variant="outline"
                 onClick={() => triggerRankMutation.mutate({ roundId })}
                 disabled={triggerRankMutation.isPending}
-              className="flex-shrink-0"
               >
                 {triggerRankMutation.isPending ? (
                   <Loader2 className="mr-2 h-4 w-4 animate-spin" />
@@ -332,6 +394,19 @@ export function RankingDashboard({ competitionId: _competitionId, roundId }: Ran
                 )}
                 Run Ranking
               </Button>
+              <Button
+                size="sm"
+                disabled={saveReorderMutation.isPending || advanceMutation.isPending || !latestSnapshotId}
+                onClick={() => setAdvanceDialogOpen(true)}
+                className="bg-[#053d57] hover:bg-[#053d57]/90"
+              >
+                {advanceMutation.isPending ? (
+                  <><Loader2 className="h-4 w-4 mr-2 animate-spin" /> Advancing...</>
+                ) : (
+                  <><Trophy className="h-4 w-4 mr-2" /> Advance Top N</>
+                )}
+              </Button>
+            </div>
           </CardHeader>
         </Card>
 
@@ -388,6 +463,114 @@ export function RankingDashboard({ competitionId: _competitionId, roundId }: Ran
         ))}
       </div>
 
+      {/* Advance Top N dialog */}
+      <Dialog open={advanceDialogOpen} onOpenChange={setAdvanceDialogOpen}>
+        <DialogContent className="sm:max-w-md">
+          <DialogHeader>
+            <DialogTitle>Advance Top Projects</DialogTitle>
+            <DialogDescription>
+              Select how many top-ranked projects to advance to the next round per category.
+              Projects are advanced in the order shown in the ranking list.
+            </DialogDescription>
+          </DialogHeader>
+
+          <div className="space-y-4 py-2">
+            {/* Top N for STARTUP */}
+            {localOrder.STARTUP.length > 0 && (
+              <div className="flex items-center gap-3">
+                <Label className="w-40 text-sm">Startups to advance</Label>
+                <Input
+                  type="number"
+                  min={0}
+                  max={localOrder.STARTUP.length}
+                  value={topNStartup}
+                  onChange={(e) =>
+                    setTopNStartup(
+                      Math.max(0, Math.min(localOrder.STARTUP.length, parseInt(e.target.value) || 0)),
+                    )
+                  }
+                  className="w-24"
+                />
+                <span className="text-xs text-muted-foreground">of {localOrder.STARTUP.length}</span>
+              </div>
+            )}
+
+            {/* Top N for BUSINESS_CONCEPT */}
+            {localOrder.BUSINESS_CONCEPT.length > 0 && (
+              <div className="flex items-center gap-3">
+                <Label className="w-40 text-sm">Business concepts to advance</Label>
+                <Input
+                  type="number"
+                  min={0}
+                  max={localOrder.BUSINESS_CONCEPT.length}
+                  value={topNConceptual}
+                  onChange={(e) =>
+                    setTopNConceptual(
+                      Math.max(0, Math.min(localOrder.BUSINESS_CONCEPT.length, parseInt(e.target.value) || 0)),
+                    )
+                  }
+                  className="w-24"
+                />
+                <span className="text-xs text-muted-foreground">of {localOrder.BUSINESS_CONCEPT.length}</span>
+              </div>
+            )}
+
+            {/* Optional: also batch-reject non-advanced */}
+            <div className="flex items-center gap-2 pt-2 border-t">
+              <input
+                type="checkbox"
+                id="includeReject"
+                checked={includeReject}
+                onChange={(e) => setIncludeReject(e.target.checked)}
+                className="h-4 w-4 accent-[#de0f1e]"
+              />
+              <Label htmlFor="includeReject" className="text-sm cursor-pointer">
+                Also batch-reject non-advanced projects
+              </Label>
+            </div>
+
+            {/* Preview */}
+            <div className="text-xs text-muted-foreground bg-muted/50 rounded-md p-3">
+              <p>Advancing: {topNStartup + topNConceptual} projects</p>
+              {includeReject && (
+                <p>
+                  Rejecting:{' '}
+                  {localOrder.STARTUP.length - topNStartup + (localOrder.BUSINESS_CONCEPT.length - topNConceptual)}{' '}
+                  projects
+                </p>
+              )}
+            </div>
+          </div>
+
+          <DialogFooter>
+            <Button
+              variant="outline"
+              onClick={() => setAdvanceDialogOpen(false)}
+              disabled={advanceMutation.isPending || batchRejectMutation.isPending}
+            >
+              Cancel
+            </Button>
+            <Button
+              onClick={handleAdvance}
+              disabled={
+                advanceMutation.isPending ||
+                batchRejectMutation.isPending ||
+                topNStartup + topNConceptual === 0
+              }
+              className="bg-[#053d57] hover:bg-[#053d57]/90"
+            >
+              {advanceMutation.isPending ? (
+                <>
+                  <Loader2 className="h-4 w-4 mr-2 animate-spin" /> Advancing...
+                </>
+              ) : (
+                `Advance ${topNStartup + topNConceptual} Project${topNStartup + topNConceptual !== 1 ? 's' : ''}`
+              )}
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
+
       {/* Side panel Sheet */}
       <Sheet
         open={!!selectedProjectId}