Fix urlopen timeout arg + unwrap ExceptionGroup in error display

app.py

@@ -279,8 +279,11 @@ async def _gemini_stream(api_key: str, contents: list[dict]):
         method="POST",
     )
     try:
+        # `timeout` is a kwarg of urlopen; passing it positionally to
+        # asyncio.to_thread would forward it as `data` (POST body) and break
+        # the request.
         response = await asyncio.to_thread(
-            urllib.request.urlopen, request, REQUEST_TIMEOUT)
+            lambda: urllib.request.urlopen(request, timeout=REQUEST_TIMEOUT))
     except urllib.error.HTTPError as exc:
         detail = await asyncio.to_thread(exc.read)
         text = detail.decode("utf-8", "replace")[:600]
@@ -561,10 +564,21 @@ def answer(question: str):
             yield (f"**{payload[0]}**", ANSWER_PLACEHOLDER, "")
         elif kind == "error":
             exc = payload[0]
-            yield (f"**Could not complete the request.**\n\n"
-                   f"`{type(exc).__name__}: {exc}`\n\n"
-                   "The MCP service may be waking from sleep -- try again "
-                   "in a moment.", ANSWER_PLACEHOLDER, "")
+            # Unwrap ExceptionGroup (from anyio TaskGroups in the MCP client)
+            # so the user sees the actual root cause, not the wrapper.
+            lines = []
+            def _walk(e, depth=0):
+                indent = "  " * depth
+                lines.append(f"{indent}- `{type(e).__name__}: {e}`")
+                inner = getattr(e, "exceptions", None)
+                if inner:
+                    for sub in inner:
+                        _walk(sub, depth + 1)
+            _walk(exc)
+            yield ("**Could not complete the request.**\n\n"
+                   + "\n".join(lines) +
+                   "\n\nThe MCP service may be waking from sleep -- "
+                   "try again in a moment.", ANSWER_PLACEHOLDER, "")
 
 
 # --- UI -----------------------------------------------------------------------