Participants, context menus, budget rename, file types, UI polish

- Assignment participants: toggle who joins each activity
  - Chips with hover-to-remove (strikethrough effect)
  - Add button with dropdown for available members
  - Avatars in day plan sidebar
  - Side-by-side with reservation in place inspector
- Right-click context menus for places, notes in day plan + places list
- Budget categories can now be renamed (pencil icon inline edit)
- Admin: configurable allowed file types (stored in app_settings)
- File manager shows allowed types dynamically
- Hotel picker: select place + save button (no auto-close)
- Edit pencil opens full hotel popup with all options
- Place inspector: opening hours + files side by side on desktop
- Address clamped to 2 lines, coordinates hidden on mobile
- Category shows icon only on mobile
- Rating hidden on mobile in place inspector
- Time validation: "10" becomes "10:00"
- Climate weather: full hourly data from archive API
- CustomSelect: grouped headers support (isHeader)
- Various responsive fixes

server/src/db/database.js

@@ -337,6 +337,14 @@ function initDb() {
     CREATE INDEX IF NOT EXISTS idx_photos_trip_id ON photos(trip_id);
     CREATE INDEX IF NOT EXISTS idx_users_email ON users(email);
     CREATE INDEX IF NOT EXISTS idx_day_accommodations_trip_id ON day_accommodations(trip_id);
+
+    CREATE TABLE IF NOT EXISTS assignment_participants (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      assignment_id INTEGER NOT NULL REFERENCES day_assignments(id) ON DELETE CASCADE,
+      user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+      UNIQUE(assignment_id, user_id)
+    );
+    CREATE INDEX IF NOT EXISTS idx_assignment_participants_assignment ON assignment_participants(assignment_id);
   `);
 
   // Versioned migrations — each runs exactly once
@@ -438,6 +446,17 @@ function initDb() {
     () => {
       try { _db.exec('ALTER TABLE reservations ADD COLUMN assignment_id INTEGER REFERENCES day_assignments(id) ON DELETE SET NULL'); } catch {}
     },
+    // 24: Assignment participants (who's joining which activity)
+    () => {
+      _db.exec(`
+        CREATE TABLE IF NOT EXISTS assignment_participants (
+          id INTEGER PRIMARY KEY AUTOINCREMENT,
+          assignment_id INTEGER NOT NULL REFERENCES day_assignments(id) ON DELETE CASCADE,
+          user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+          UNIQUE(assignment_id, user_id)
+        )
+      `);
+    },
     // Future migrations go here (append only, never reorder)
   ];