Add debug output for relay URL update issue

- Always trigger on_session_id callback when server returns session ID
- Add debug prints to trace URL update flow

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

relay_client.py

@@ -144,7 +144,8 @@ class RelayClient:
                 # Mark as connected before callbacks so update_ip_label works
                 self._connected = True
                 new_session_id = response.get("sessionId")
-                if new_session_id and new_session_id != self.session_id:
+                # Always update session_id and trigger callback to ensure URL updates
+                if new_session_id:
                     self.session_id = new_session_id
                     if self.on_session_id:
                         self.on_session_id(new_session_id)