feat: room search, room options sheet, .htaccess for E2EE

- Rooms screen: inline search filter with toggle — replaces the no-op button
- Chat screen: room options sheet — member list, invite, leave room
- rooms_repository: remove debug prints
- web/.htaccess: COOP+COEP headers for SharedArrayBuffer / LiveKit E2EE worker
  (was on production but missing from source; adds it to build output automatically)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/features/rooms/data/rooms_repository.dart

@@ -1,8 +1,7 @@
-// Version: 1.2.0 | Created: 2026-04-01 | Updated: 2026-04-02
+// Version: 1.3.0 | Created: 2026-04-01 | Updated: 2026-04-27
 // Rooms repository. Reads room list from the Matrix SDK client.
 
 import 'package:matrix/matrix.dart';
-import 'package:flutter/foundation.dart';
 import 'package:riverpod_annotation/riverpod_annotation.dart';
 
 import '../../../core/network/matrix_client.dart';
@@ -25,10 +24,6 @@ class RoomsRepository {
   /// Returns the current room list, sorted unread-first then by last activity.
   List<RoomModel> getRooms() {
     final rooms = _client.rooms;
-    debugPrint('[Rooms] client.rooms count: ${rooms.length}');
-    for (final r in rooms) {
-      debugPrint('[Rooms]   ${r.id} "${r.getLocalizedDisplayname()}" isSpace=${r.isSpace}');
-    }
     final models = rooms.map(_toModel).toList();
 
     models.sort((a, b) {