feat(finalist): deadline reminder emails via cron

Add sendDueConfirmationReminders() to finalist-confirmation.ts: queries
PENDING confirmations with no reminderSentAt whose deadline is within the
per-program LIVE_FINAL round reminderHoursBeforeDeadline window (default 12h),
sends a FINALIST_REMINDER in-app notification (+ email via pipeline) to the
team LEAD, then stamps reminderSentAt for idempotency.

Wire into the finalist-confirmations cron route alongside expirePendingPastDeadline.
Also clear reminderSentAt on re-invite in resetOrCreatePendingConfirmation so
re-invited teams get a fresh reminder window.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/server/services/finalist-confirmation.ts

@@ -2,7 +2,7 @@ import type { CompetitionCategory, PrismaClient } from '@prisma/client'
 import { signFinalistToken } from '@/lib/finalist-token'
 import { sendFinalistConfirmationEmail } from '@/lib/email'
 import { logAudit } from '@/server/utils/audit'
-import { notifyAdmins, NotificationTypes } from './in-app-notification'
+import { notifyAdmins, createNotification, NotificationTypes } from './in-app-notification'
 
 type AnyPrisma = Pick<PrismaClient, 'finalistConfirmation' | 'waitlistEntry' | 'project'>
 
@@ -198,3 +198,116 @@ export async function expirePendingPastDeadline(
   }
   return { expired: expired.length, promoted }
 }
+
+/**
+ * Cron entrypoint: send pre-deadline confirmation reminders.
+ *
+ * For each PENDING confirmation that has not yet received a reminder
+ * (reminderSentAt IS NULL) and whose deadline is still in the future but
+ * within the program's configured `reminderHoursBeforeDeadline` window
+ * (default 12 h), send a FINALIST_REMINDER in-app notification (+ email via
+ * the notification pipeline) to the project's LEAD team member, then stamp
+ * `reminderSentAt` so the row is never processed again.
+ *
+ * Best-effort per row — a failure on one row never aborts the rest.
+ */
+export async function sendDueConfirmationReminders(
+  prisma: PrismaClient,
+): Promise<{ remindersSent: number }> {
+  const now = new Date()
+
+  // Load all candidates: PENDING, no reminder sent yet, deadline still future.
+  const candidates = await prisma.finalistConfirmation.findMany({
+    where: {
+      status: 'PENDING',
+      reminderSentAt: null,
+      deadline: { gt: now },
+    },
+    include: {
+      project: {
+        select: {
+          id: true,
+          title: true,
+          programId: true,
+          teamMembers: {
+            where: { role: 'LEAD' },
+            take: 1,
+            select: {
+              userId: true,
+              user: { select: { name: true } },
+            },
+          },
+        },
+      },
+    },
+  })
+
+  if (candidates.length === 0) return { remindersSent: 0 }
+
+  // Cache reminderHoursBeforeDeadline per programId to avoid repeat queries.
+  const reminderHoursCache = new Map<string, number>()
+
+  async function getReminderHours(programId: string): Promise<number> {
+    if (reminderHoursCache.has(programId)) {
+      return reminderHoursCache.get(programId)!
+    }
+    const round = await prisma.round.findFirst({
+      where: {
+        competition: { programId },
+        roundType: 'LIVE_FINAL',
+      },
+      orderBy: { sortOrder: 'desc' },
+      select: { configJson: true },
+    })
+    const cfg = (round?.configJson ?? {}) as { reminderHoursBeforeDeadline?: number }
+    const hours = cfg.reminderHoursBeforeDeadline ?? 12
+    reminderHoursCache.set(programId, hours)
+    return hours
+  }
+
+  const baseUrl = (process.env.NEXTAUTH_URL ?? 'http://localhost:3000').replace(/\/$/, '')
+  let remindersSent = 0
+
+  for (const row of candidates) {
+    try {
+      const reminderHours = await getReminderHours(row.project.programId)
+      const windowMs = reminderHours * 3_600_000
+      const isDue = row.deadline.getTime() <= now.getTime() + windowMs
+
+      if (!isDue) continue
+
+      const lead = row.project.teamMembers[0]
+      if (!lead) continue
+
+      const confirmUrl = `${baseUrl}/finalist/confirm/${row.token}`
+      const title = row.project.title
+
+      await createNotification({
+        userId: lead.userId,
+        type: NotificationTypes.FINALIST_REMINDER,
+        title: 'Reminder: confirm your grand-finale attendance',
+        message: `Please confirm attendance for "${title}" before the deadline.`,
+        linkUrl: confirmUrl,
+        metadata: {
+          projectTitle: title,
+          projectId: row.project.id,
+          deadline: row.deadline.toISOString(),
+        },
+      })
+
+      await prisma.finalistConfirmation.update({
+        where: { id: row.id },
+        data: { reminderSentAt: new Date() },
+      })
+
+      remindersSent++
+    } catch (err) {
+      console.error(
+        `[sendDueConfirmationReminders] failed for confirmation ${row.id} (project ${row.projectId}):`,
+        err,
+      )
+    }
+  }
+
+  return { remindersSent }
+}

src/server/services/finalist-enrollment.ts

@@ -43,6 +43,7 @@ export async function resetOrCreatePendingConfirmation(
         declinedAt: null,
         declineReason: null,
         expiredAt: null,
+        reminderSentAt: null,
       },
     })
     return { id: existing.id, token, deadline, alreadyConfirmed: false }