feat: lunch.getEvent + lunch.updateEvent procedures

Lazy-creates LunchEvent on first read or update. Audit-logs every
update with the patched fields.

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

src/server/routers/_app.ts

@@ -52,6 +52,7 @@ import { resultLockRouter } from './resultLock'
 // Grand-finale logistics
 import { finalistRouter } from './finalist'
 import { logisticsRouter } from './logistics'
+import { lunchRouter } from './lunch'
 
 /**
  * Root tRPC router that combines all domain routers
@@ -110,6 +111,7 @@ export const appRouter = router({
   // Grand-finale logistics
   finalist: finalistRouter,
   logistics: logisticsRouter,
+  lunch: lunchRouter,
 })
 
 export type AppRouter = typeof appRouter

src/server/routers/lunch.ts

@@ -0,0 +1,81 @@
+import { z } from 'zod'
+import { TRPCError } from '@trpc/server'
+import { router, adminProcedure, protectedProcedure } from '../trpc'
+import { logAudit } from '../utils/audit'
+
+// ─── Shared zod schemas ──────────────────────────────────────────────────────
+
+const dietaryTags = z.array(
+  z.enum(['VEGETARIAN', 'VEGAN', 'GLUTEN_FREE', 'PESCATARIAN']),
+)
+
+const allergens = z.array(
+  z.enum([
+    'GLUTEN', 'CRUSTACEANS', 'EGGS', 'FISH', 'PEANUTS', 'SOYBEANS', 'MILK',
+    'TREE_NUTS', 'CELERY', 'MUSTARD', 'SESAME', 'SULPHITES', 'LUPIN', 'MOLLUSCS',
+  ]),
+)
+
+// ─── Router ──────────────────────────────────────────────────────────────────
+
+export const lunchRouter = router({
+  /**
+   * Get-or-create the LunchEvent for a program. Lazy creation mirrors
+   * the hotel pattern: callers don't have to know whether the row
+   * already exists.
+   */
+  getEvent: adminProcedure
+    .input(z.object({ programId: z.string() }))
+    .query(async ({ ctx, input }) => {
+      const existing = await ctx.prisma.lunchEvent.findUnique({
+        where: { programId: input.programId },
+      })
+      if (existing) return existing
+      return ctx.prisma.lunchEvent.create({ data: { programId: input.programId } })
+    }),
+
+  /** Patch any subset of LunchEvent config fields. Audit-logged. */
+  updateEvent: adminProcedure
+    .input(
+      z.object({
+        programId: z.string(),
+        enabled: z.boolean().optional(),
+        eventAt: z.date().nullable().optional(),
+        endAt: z.date().nullable().optional(),
+        venue: z.string().nullable().optional(),
+        notes: z.string().nullable().optional(),
+        changeCutoffHours: z.number().int().min(0).max(720).optional(),
+        reminderHoursBeforeDeadline: z
+          .number()
+          .int()
+          .min(0)
+          .max(720)
+          .nullable()
+          .optional(),
+        cronEnabled: z.boolean().optional(),
+        extraRecipients: z.array(z.string().email()).optional(),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const { programId, ...patch } = input
+      // Lazy-create before patching so updateEvent doubles as "create + update"
+      await ctx.prisma.lunchEvent.upsert({
+        where: { programId },
+        create: { programId },
+        update: {},
+      })
+      const updated = await ctx.prisma.lunchEvent.update({
+        where: { programId },
+        data: patch,
+      })
+      await logAudit({
+        prisma: ctx.prisma,
+        userId: ctx.user.id,
+        action: 'LUNCH_EVENT_UPDATED',
+        entityType: 'LunchEvent',
+        entityId: updated.id,
+        detailsJson: patch as Record<string, unknown>,
+      })
+      return updated
+    }),
+})