v2.1.0 — Real-time collaboration, performance & security overhaul

Real-Time Collaboration (WebSocket):
- WebSocket server with JWT auth and trip-based rooms
- Live sync for all CRUD operations (places, assignments, days, notes, budget, packing, reservations, files)
- Socket-based exclusion to prevent duplicate updates
- Auto-reconnect with exponential backoff
- Assignment move sync between days

Performance:
- 16 database indexes on all foreign key columns
- N+1 query fix in places, assignments and days endpoints
- Marker clustering (react-leaflet-cluster) with configurable radius
- List virtualization (react-window) for places sidebar
- useMemo for filtered places
- SQLite WAL mode + busy_timeout for concurrent writes
- Weather API: server-side cache (1h forecast, 15min current) + client sessionStorage
- Google Places photos: persisted to DB after first fetch
- Google Details: 3-tier cache (memory → sessionStorage → API)

Security:
- CORS auto-configuration (production: same-origin, dev: open)
- API keys removed from /auth/me response
- Admin-only endpoint for reading API keys
- Path traversal prevention in cover image deletion
- JWT secret persisted to file (survives restarts)
- Avatar upload file extension whitelist
- API key fallback: normal users use admin's key without exposure
- Case-insensitive email login

Dark Mode:
- Fixed hardcoded colors across PackingList, Budget, ReservationModal, ReservationsPanel
- Mobile map buttons and sidebar sheets respect dark mode
- Cluster markers always dark

UI/UX:
- Redesigned login page with animated planes, stars and feature cards
- Admin: create user functionality with CustomSelect
- Mobile: day-picker popup for assigning places to days
- Mobile: touch-friendly reorder buttons (32px targets)
- Mobile: responsive text (shorter labels on small screens)
- Packing list: index-based category colors
- i18n: translated date picker placeholder, fixed German labels
- Default map tile: CartoDB Light

server/src/db/database.js

@@ -21,6 +21,7 @@ function initDb() {
 
   _db = new DatabaseSync(dbPath);
   _db.exec('PRAGMA journal_mode = WAL');
+  _db.exec('PRAGMA busy_timeout = 5000');
   _db.exec('PRAGMA foreign_keys = ON');
 
   // Create all tables
@@ -212,6 +213,26 @@ function initDb() {
     );
   `);
 
+  // Create indexes for performance
+  _db.exec(`
+    CREATE INDEX IF NOT EXISTS idx_places_trip_id ON places(trip_id);
+    CREATE INDEX IF NOT EXISTS idx_places_category_id ON places(category_id);
+    CREATE INDEX IF NOT EXISTS idx_days_trip_id ON days(trip_id);
+    CREATE INDEX IF NOT EXISTS idx_day_assignments_day_id ON day_assignments(day_id);
+    CREATE INDEX IF NOT EXISTS idx_day_assignments_place_id ON day_assignments(place_id);
+    CREATE INDEX IF NOT EXISTS idx_place_tags_place_id ON place_tags(place_id);
+    CREATE INDEX IF NOT EXISTS idx_place_tags_tag_id ON place_tags(tag_id);
+    CREATE INDEX IF NOT EXISTS idx_trip_members_trip_id ON trip_members(trip_id);
+    CREATE INDEX IF NOT EXISTS idx_trip_members_user_id ON trip_members(user_id);
+    CREATE INDEX IF NOT EXISTS idx_packing_items_trip_id ON packing_items(trip_id);
+    CREATE INDEX IF NOT EXISTS idx_budget_items_trip_id ON budget_items(trip_id);
+    CREATE INDEX IF NOT EXISTS idx_reservations_trip_id ON reservations(trip_id);
+    CREATE INDEX IF NOT EXISTS idx_trip_files_trip_id ON trip_files(trip_id);
+    CREATE INDEX IF NOT EXISTS idx_day_notes_day_id ON day_notes(day_id);
+    CREATE INDEX IF NOT EXISTS idx_photos_trip_id ON photos(trip_id);
+    CREATE INDEX IF NOT EXISTS idx_users_email ON users(email);
+  `);
+
   // Migrations
   const migrations = [
     `ALTER TABLE users ADD COLUMN unsplash_api_key TEXT`,