feat(gateway): add Feishu websocket ping timing overrides

Allow Feishu websocket keepalive timing to be configured via platform
extra config so disconnects can be detected faster in unstable networks.

New optional extra settings:
- ws_ping_interval
- ws_ping_timeout

These values are applied only when explicitly configured. Invalid values
fall back to the websocket library defaults by leaving the options unset.

This complements the reconnect timing settings added previously and helps
reduce total recovery time after network interruptions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/gateway/test_feishu.py

@@ -587,6 +587,32 @@ class TestAdapterModule(unittest.TestCase):
         self.assertEqual(settings.ws_reconnect_nonce, 0)
         self.assertEqual(settings.ws_reconnect_interval, 3)
 
+    def test_load_settings_accepts_custom_ws_ping_values(self):
+        from gateway.platforms.feishu import FeishuAdapter
+
+        settings = FeishuAdapter._load_settings(
+            {
+                "ws_ping_interval": 10,
+                "ws_ping_timeout": 8,
+            }
+        )
+
+        self.assertEqual(settings.ws_ping_interval, 10)
+        self.assertEqual(settings.ws_ping_timeout, 8)
+
+    def test_load_settings_ignores_invalid_ws_ping_values(self):
+        from gateway.platforms.feishu import FeishuAdapter
+
+        settings = FeishuAdapter._load_settings(
+            {
+                "ws_ping_interval": 0,
+                "ws_ping_timeout": -1,
+            }
+        )
+
+        self.assertIsNone(settings.ws_ping_interval)
+        self.assertIsNone(settings.ws_ping_timeout)
+
 
 class TestAdapterBehavior(unittest.TestCase):
     @patch.dict(os.environ, {}, clear=True)