feat: add caching for backend objects

supabase/functions/create-reservation/index.ts

@@ -110,6 +110,20 @@ Deno.serve(async (req: Request) => {
     return errorResponse('invalid_dates', 'end_time must be after start_time', 400)
   }
 
+  // ── Historical booking guard ────────────────────────────────────────────────
+  const isPast = endDate.getTime() < Date.now()
+
+  if (isPast) {
+    const { data: callerMember } = await adminClient
+      .from('members')
+      .select('role')
+      .eq('user_id', userId)
+      .single()
+    if (callerMember?.role !== 'admin') {
+      return errorResponse('historical_booking_not_allowed', 'Can not book a reservation in the past.', 422)
+    }
+  }
+
   // ── 1. Load booking config ──────────────────────────────────────────────────
   const { data: configRows, error: configErr } = await adminClient
     .from('booking_config')
@@ -142,7 +156,7 @@ Deno.serve(async (req: Request) => {
   if (boatErr || !boat) return errorResponse('not_found', 'Boat not found', 404)
   if (!boat.booking_available) return errorResponse('boat_unavailable', 'This boat is currently out of service', 422)
 
-  if (boat.required_certs.length > 0) {
+  if (!isPast && boat.required_certs.length > 0) {
     const { data: member } = await adminClient
       .from('members')
       .select('certifications')
@@ -164,7 +178,7 @@ Deno.serve(async (req: Request) => {
   const advanceMs = config.open_session_advance_hours * 60 * 60 * 1000
   const isOpenSession = startDate.getTime() - Date.now() <= advanceMs
 
-  if (!isOpenSession) {
+  if (!isPast && !isOpenSession) {
     // ── 5. Weekly pre-booking limit ─────────────────────────────────────────
     const weekStart = isoWeekStart(startDate)
     const weekEnd   = new Date(weekStart.getTime() + 7 * 24 * 60 * 60 * 1000)