feat: Add Chat UX improvements with notifications and @mention support

- Add ActionBar component with expandable toolbar for mobile
- Add @mention functionality with autocomplete dropdown
- Add browser notification system (push, sound, vibration)
- Add NotificationSettings modal for user preferences
- Add mention badges on room list cards
- Add ReportPreview with Markdown rendering and copy/download
- Add message copy functionality with hover actions
- Add backend mentions field to messages with Alembic migration
- Add lots field to rooms, remove templates
- Optimize WebSocket database session handling
- Various UX polish (animations, accessibility)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

app/modules/chat_room/router.py

@@ -13,7 +13,6 @@ from app.modules.chat_room import schemas
 from app.modules.chat_room.models import MemberRole, RoomStatus
 from app.modules.chat_room.services.room_service import room_service
 from app.modules.chat_room.services.membership_service import membership_service
-from app.modules.chat_room.services.template_service import template_service
 from app.modules.chat_room.dependencies import (
     get_current_room,
     require_room_permission,
@@ -36,25 +35,7 @@ async def create_room(
     """Create a new incident room"""
     user_email = current_user["username"]
 
-    # Check if using template
-    if room_data.template:
-        template = template_service.get_template_by_name(db, room_data.template)
-        if template:
-            room = template_service.create_room_from_template(
-                db,
-                template.template_id,
-                user_email,
-                room_data.title,
-                room_data.location,
-                room_data.description
-            )
-        else:
-            raise HTTPException(
-                status_code=status.HTTP_400_BAD_REQUEST,
-                detail=f"Template '{room_data.template}' not found"
-            )
-    else:
-        room = room_service.create_room(db, user_email, room_data)
+    room = room_service.create_room(db, user_email, room_data)
 
     # Get user role for response
     role = membership_service.get_user_role_in_room(db, room.room_id, user_email)
@@ -508,12 +489,56 @@ async def get_user_permissions(
     return permissions[role]
 
 
-# Template Endpoints
-@router.get("/templates", response_model=List[schemas.TemplateResponse])
-async def list_templates(
-    db: Session = Depends(get_db),
-    _: dict = Depends(get_current_user)
+# LOT Endpoints
+@router.post("/{room_id}/lots", response_model=List[str])
+async def add_lot(
+    room_id: str,
+    request: schemas.AddLotRequest,
+    _: None = Depends(require_room_permission("update_metadata")),
+    db: Session = Depends(get_db)
 ):
-    """List available room templates"""
-    templates = template_service.get_templates(db)
-    return [schemas.TemplateResponse.from_orm(t) for t in templates]
+    """Add a LOT batch number to the room"""
+    from app.modules.chat_room.models import IncidentRoom
+
+    room = db.query(IncidentRoom).filter(IncidentRoom.room_id == room_id).first()
+    if not room:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Room not found")
+
+    # Get current lots or initialize empty list
+    current_lots = room.lots or []
+
+    # Prevent duplicates
+    if request.lot not in current_lots:
+        current_lots.append(request.lot)
+        room.lots = current_lots
+        room.last_updated_at = datetime.utcnow()
+        db.commit()
+        db.refresh(room)
+
+    return room.lots
+
+
+@router.delete("/{room_id}/lots/{lot}", response_model=List[str])
+async def remove_lot(
+    room_id: str,
+    lot: str,
+    _: None = Depends(require_room_permission("update_metadata")),
+    db: Session = Depends(get_db)
+):
+    """Remove a LOT batch number from the room"""
+    from app.modules.chat_room.models import IncidentRoom
+
+    room = db.query(IncidentRoom).filter(IncidentRoom.room_id == room_id).first()
+    if not room:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Room not found")
+
+    current_lots = room.lots or []
+
+    if lot in current_lots:
+        current_lots.remove(lot)
+        room.lots = current_lots
+        room.last_updated_at = datetime.utcnow()
+        db.commit()
+        db.refresh(room)
+
+    return room.lots