feat: per-category finalist slot quotas with confirmed-count guard

src/server/routers/_app.ts

@@ -49,6 +49,8 @@ import { roundEngineRouter } from './roundEngine'
 import { roundAssignmentRouter } from './roundAssignment'
 import { deliberationRouter } from './deliberation'
 import { resultLockRouter } from './resultLock'
+// Grand-finale logistics
+import { finalistRouter } from './finalist'
 
 /**
  * Root tRPC router that combines all domain routers
@@ -104,6 +106,8 @@ export const appRouter = router({
   roundAssignment: roundAssignmentRouter,
   deliberation: deliberationRouter,
   resultLock: resultLockRouter,
+  // Grand-finale logistics
+  finalist: finalistRouter,
 })
 
 export type AppRouter = typeof appRouter

src/server/routers/finalist.ts

@@ -0,0 +1,64 @@
+import { z } from 'zod'
+import { TRPCError } from '@trpc/server'
+import { CompetitionCategory } from '@prisma/client'
+import { router, adminProcedure } from '../trpc'
+import { logAudit } from '../utils/audit'
+
+export const finalistRouter = router({
+  /**
+   * Set the finalist slot quota for a category in a program. Mutable mid-flight,
+   * but blocked when reducing below the count of already-CONFIRMED finalists in
+   * that category — admin must un-confirm a team first.
+   */
+  setQuota: adminProcedure
+    .input(
+      z.object({
+        programId: z.string(),
+        category: z.nativeEnum(CompetitionCategory),
+        quota: z.number().int().min(0).max(100),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const confirmedCount = await ctx.prisma.finalistConfirmation.count({
+        where: {
+          project: { programId: input.programId },
+          category: input.category,
+          status: 'CONFIRMED',
+        },
+      })
+      if (input.quota < confirmedCount) {
+        throw new TRPCError({
+          code: 'BAD_REQUEST',
+          message: `Cannot reduce ${input.category} quota to ${input.quota} — ${confirmedCount} teams have already confirmed. Un-confirm one team first, then retry.`,
+        })
+      }
+      const quota = await ctx.prisma.finalistSlotQuota.upsert({
+        where: {
+          programId_category: {
+            programId: input.programId,
+            category: input.category,
+          },
+        },
+        create: {
+          programId: input.programId,
+          category: input.category,
+          quota: input.quota,
+        },
+        update: { quota: input.quota },
+      })
+      await logAudit({
+        prisma: ctx.prisma,
+        userId: ctx.user.id,
+        action: 'FINALIST_QUOTA_SET',
+        entityType: 'FinalistSlotQuota',
+        entityId: quota.id,
+        detailsJson: {
+          programId: input.programId,
+          category: input.category,
+          quota: input.quota,
+          previousConfirmedCount: confirmedCount,
+        },
+      })
+      return quota
+    }),
+})