feat: add reply/forward/pin message flow across backend and web

- add reply_to/forwarded_from message fields and chat pinned_message field

- add forward and pin APIs plus reply support in message create

- wire web actions: Reply, Fwd, Pin and reply composer state

- fix spam policy bug: allow repeated identical messages, keep rate limiting

app/messages/router.py

@@ -3,8 +3,8 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.auth.service import get_current_user
 from app.database.session import get_db
-from app.messages.schemas import MessageCreateRequest, MessageRead, MessageStatusUpdateRequest, MessageUpdateRequest
-from app.messages.service import create_chat_message, delete_message, get_messages, search_messages, update_message
+from app.messages.schemas import MessageCreateRequest, MessageForwardRequest, MessageRead, MessageStatusUpdateRequest, MessageUpdateRequest
+from app.messages.service import create_chat_message, delete_message, forward_message, get_messages, search_messages, update_message
 from app.realtime.schemas import MessageStatusPayload
 from app.realtime.service import realtime_gateway
 from app.users.models import User
@@ -80,3 +80,15 @@ async def update_status(
         payload=MessageStatusPayload(chat_id=payload.chat_id, message_id=payload.message_id),
         event=payload.status,
     )
+
+
+@router.post("/{message_id}/forward", response_model=MessageRead, status_code=status.HTTP_201_CREATED)
+async def forward_message_endpoint(
+    message_id: int,
+    payload: MessageForwardRequest,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user),
+) -> MessageRead:
+    message = await forward_message(db, source_message_id=message_id, sender_id=current_user.id, payload=payload)
+    await realtime_gateway.publish_message_created(message=message, sender_id=current_user.id)
+    return message