feat(chat): add in-message attachments gallery and multi-file send

app/media/router.py

@@ -3,8 +3,10 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.auth.service import get_current_user
 from app.database.session import get_db
+from app.messages.repository import get_message_by_id
 from app.media.schemas import AttachmentCreateRequest, AttachmentRead, ChatAttachmentRead, UploadUrlRequest, UploadUrlResponse
 from app.media.service import generate_upload_url, list_attachments_for_chat, store_attachment_metadata
+from app.realtime.service import realtime_gateway
 from app.users.models import User
 
 router = APIRouter(prefix="/media", tags=["media"])
@@ -24,7 +26,11 @@ async def create_attachment_metadata(
     db: AsyncSession = Depends(get_db),
     current_user: User = Depends(get_current_user),
 ) -> AttachmentRead:
-    return await store_attachment_metadata(db, user_id=current_user.id, payload=payload)
+    attachment = await store_attachment_metadata(db, user_id=current_user.id, payload=payload)
+    message = await get_message_by_id(db, attachment.message_id)
+    if message:
+        await realtime_gateway.publish_chat_updated(chat_id=message.chat_id)
+    return attachment
 
 
 @router.get("/chats/{chat_id}/attachments", response_model=list[ChatAttachmentRead])