feat: add multi-tab support to remote browser

backend/app/routers/browser_sessions.py

@@ -34,11 +34,21 @@ class BrowserSessionCreate(BaseModel):
     height: int = Field(default=720)
 
 
+class BrowserTabResponse(BaseModel):
+    id: str
+    title: str
+    url: str
+    created_at: float
+
+
 class BrowserSessionResponse(BaseModel):
     id: str
     custom_page_id: int
     url: str
     title: str
+    active_tab_id: Optional[str] = None
+    tabs: Optional[list[BrowserTabResponse]] = None
+    tab_revision: Optional[int] = 0
 
 
 class BrowserSelectionResponse(BaseModel):
@@ -123,6 +133,22 @@ async def send_event(session_id: str, body: BrowserEvent, _=Depends(get_current_
         raise _error_from_browser(exc)
 
 
+@router.post("/{session_id}/tabs/{tab_id}/activate", response_model=BrowserSessionResponse)
+async def activate_tab(session_id: str, tab_id: str, _=Depends(get_current_user)):
+    try:
+        return await browser_sessions.activate_tab(session_id, tab_id)
+    except Exception as exc:
+        raise _error_from_browser(exc)
+
+
+@router.delete("/{session_id}/tabs/{tab_id}", response_model=BrowserSessionResponse)
+async def close_tab(session_id: str, tab_id: str, _=Depends(get_current_user)):
+    try:
+        return await browser_sessions.close_tab(session_id, tab_id)
+    except Exception as exc:
+        raise _error_from_browser(exc)
+
+
 @router.get("/{session_id}/selection", response_model=BrowserSelectionResponse)
 async def get_selection(session_id: str, _=Depends(get_current_user)):
     try:
@@ -314,6 +340,7 @@ async def session_ws(
     # Task: push screenshots
     async def push_loop():
         nonlocal last_frame_hash, unchanged_count
+        last_tab_revision = -1
         try:
             while True:
                 now = asyncio.get_event_loop().time()
@@ -327,6 +354,13 @@ async def session_ws(
                     interval = _WS_IDLE_INTERVAL
 
                 try:
+                    # Check for tab state changes
+                    session_obj = browser_sessions.get_session(session_id)
+                    if session_obj.tab_revision != last_tab_revision:
+                        last_tab_revision = session_obj.tab_revision
+                        state = await browser_sessions.state(session_id)
+                        await websocket.send_json({"type": "state", "session": state})
+
                     frame = await browser_sessions.screenshot(session_id)
                 except KeyError:
                     await websocket.send_json({"error": "session_not_found"})