fix(gateway): wait for reconnection before dropping WebSocket sends

When a WebSocket-based platform adapter (e.g. QQ Bot) temporarily
loses its connection, send() now polls is_connected for up to 15s
instead of immediately returning a non-retryable failure. If the
auto-reconnect completes within the window, the message is delivered
normally. On timeout, the SendResult is marked retryable=True so the
base class retry mechanism can attempt re-delivery.

Same treatment applied to _send_media().

Adds 4 async tests covering:
- Successful send after simulated reconnection
- Retryable failure on timeout
- Immediate success when already connected
- _send_media reconnection wait

Fixes #11163

tests/gateway/test_qqbot.py

@@ -500,3 +500,85 @@ class TestBuildTextBody:
         adapter = self._make_adapter(app_id="a", client_secret="b", markdown_support=False)
         body = adapter._build_text_body("reply text", reply_to="msg_123")
         assert body.get("message_reference", {}).get("message_id") == "msg_123"
+
+
+# ---------------------------------------------------------------------------
+# _wait_for_reconnection / send reconnection wait
+# ---------------------------------------------------------------------------
+
+class TestWaitForReconnection:
+    """Test that send() waits for reconnection instead of silently dropping."""
+
+    def _make_adapter(self, **extra):
+        from gateway.platforms.qqbot import QQAdapter
+        return QQAdapter(_make_config(**extra))
+
+    @pytest.mark.asyncio
+    async def test_send_waits_and_succeeds_on_reconnect(self):
+        """send() should wait for reconnection and then deliver the message."""
+        adapter = self._make_adapter(app_id="a", client_secret="b")
+        # Initially disconnected
+        adapter._running = False
+        adapter._http_client = mock.MagicMock()
+
+        # Simulate reconnection after 0.3s (faster than real interval)
+        async def fake_api_request(*args, **kwargs):
+            return {"id": "msg_123"}
+
+        adapter._api_request = fake_api_request
+        adapter._ensure_token = mock.AsyncMock()
+        adapter._RECONNECT_POLL_INTERVAL = 0.1
+        adapter._RECONNECT_WAIT_SECONDS = 5.0
+
+        # Schedule reconnection after a short delay
+        async def reconnect_after_delay():
+            await asyncio.sleep(0.3)
+            adapter._running = True
+
+        asyncio.get_event_loop().create_task(reconnect_after_delay())
+
+        result = await adapter.send("test_openid", "Hello, world!")
+        assert result.success
+        assert result.message_id == "msg_123"
+
+    @pytest.mark.asyncio
+    async def test_send_returns_retryable_after_timeout(self):
+        """send() should return retryable=True if reconnection takes too long."""
+        adapter = self._make_adapter(app_id="a", client_secret="b")
+        adapter._running = False
+        adapter._RECONNECT_POLL_INTERVAL = 0.05
+        adapter._RECONNECT_WAIT_SECONDS = 0.2
+
+        result = await adapter.send("test_openid", "Hello, world!")
+        assert not result.success
+        assert result.retryable is True
+        assert "Not connected" in result.error
+
+    @pytest.mark.asyncio
+    async def test_send_succeeds_immediately_when_connected(self):
+        """send() should not wait when already connected."""
+        adapter = self._make_adapter(app_id="a", client_secret="b")
+        adapter._running = True
+        adapter._http_client = mock.MagicMock()
+
+        async def fake_api_request(*args, **kwargs):
+            return {"id": "msg_immediate"}
+
+        adapter._api_request = fake_api_request
+
+        result = await adapter.send("test_openid", "Hello!")
+        assert result.success
+        assert result.message_id == "msg_immediate"
+
+    @pytest.mark.asyncio
+    async def test_send_media_waits_for_reconnect(self):
+        """_send_media should also wait for reconnection."""
+        adapter = self._make_adapter(app_id="a", client_secret="b")
+        adapter._running = False
+        adapter._RECONNECT_POLL_INTERVAL = 0.05
+        adapter._RECONNECT_WAIT_SECONDS = 0.2
+
+        result = await adapter._send_media("test_openid", "http://example.com/img.jpg", 1, "image")
+        assert not result.success
+        assert result.retryable is True
+        assert "Not connected" in result.error