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