fix(bookings): preserve accommodation dates when place is unlinked or missing

- Remove NOT NULL constraint on day_accommodations.place_id (migration)
  and change ON DELETE CASCADE → SET NULL so deleting a place no longer
  cascades to the accommodation row
- Switch listAccommodations / getAccommodationWithPlace to LEFT JOIN so
  accommodations without a linked place are visible to the modal
- Relax create/update guards in reservationService to only require
  start_day_id + end_day_id, not place_id; place_id remains optional
- Client save guard now sends create_accommodation whenever FROM/TO days
  are set, regardless of whether a hotel place was selected
- Add re-hydration useEffect in ReservationModal to back-fill hotel
  fields from the accommodations prop when it arrives after modal opens
  (race between isOpen and the tripAccommodations fetch)
- Fix demo-seed TDZ crash: move db Proxy declaration before DEMO_MODE
  block so circular require in demo-reset resolves correctly
- Sidebar accommodation badge falls back to reservation title when
  place_name is null; click/cursor disabled for placeless accommodations
- listAccommodations now joins reservations to expose reservation_title

server/src/db/database.ts

@@ -35,15 +35,6 @@ function initDb(): void {
 
 initDb();
 
-if (process.env.DEMO_MODE === 'true') {
-  try {
-    const { seedDemoData } = require('../demo/demo-seed');
-    seedDemoData(_db);
-  } catch (err: unknown) {
-    console.error('[Demo] Seed error:', err instanceof Error ? err.message : err);
-  }
-}
-
 const db = new Proxy({} as Database.Database, {
   get(_, prop: string | symbol) {
     if (!_db) throw new Error('Database connection is not available (restore in progress?)');
@@ -56,6 +47,15 @@ const db = new Proxy({} as Database.Database, {
   },
 });
 
+if (process.env.DEMO_MODE === 'true') {
+  try {
+    const { seedDemoData } = require('../demo/demo-seed');
+    seedDemoData(_db);
+  } catch (err: unknown) {
+    console.error('[Demo] Seed error:', err instanceof Error ? err.message : err);
+  }
+}
+
 function closeDb(): void {
   if (_db) {
     try { _db.exec('PRAGMA wal_checkpoint(TRUNCATE)'); } catch (e) {}