Access captcha: special case for websocket

There doesn't seem to be a way to catch a 403 Forbidden error opening a
websocket with JavaScript, so this commit changes the behaviour to this:
open the websocket normally, send one "kick" message, close the
websocket.

anonstream/routes/websocket.py

@@ -9,16 +9,21 @@ from anonstream.websocket import websocket_outbound, websocket_inbound
 from anonstream.routes.wrappers import with_user_from
 
 @current_app.websocket('/live')
-@with_user_from(websocket)
-async def live(timestamp, user):
-    queue = asyncio.Queue()
-    user['websockets'][queue] = timestamp
-    reading(user, timestamp=timestamp)
+@with_user_from(websocket, fallback_to_token=True)
+async def live(timestamp, user_or_token):
+    match user_or_token:
+        case str() | None:
+            await websocket.send_json({'type': 'kick'})
+            await websocket.close(1001)
+        case dict() as user:
+            queue = asyncio.Queue()
+            user['websockets'][queue] = timestamp
+            reading(user, timestamp=timestamp)
 
-    producer = websocket_outbound(queue, user)
-    consumer = websocket_inbound(queue, user)
-    try:
-        await asyncio.gather(producer, consumer)
-    finally:
-        see(user)
-        user['websockets'].pop(queue)
+            producer = websocket_outbound(queue, user)
+            consumer = websocket_inbound(queue, user)
+            try:
+                await asyncio.gather(producer, consumer)
+            finally:
+                see(user)
+                user['websockets'].pop(queue)

anonstream/static/anonstream.js

@@ -831,6 +831,11 @@ const on_websocket_message = (event) => {
       ws.send(JSON.stringify(payload));
       break;
 
+    case "kick":
+      console.log("ws kick");
+      window.location.reload();
+      break;
+
     default:
       console.log("incomprehensible websocket message", receipt);
   }