fix(client): default_gateway never raises

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Uc9V1v7iXruubpoLiSE24M

hbd/client/gateway.py

@@ -98,6 +98,6 @@ async def default_gateway(family: str) -> Optional[str]:
             return parse_macos_route(await _run(cmd))
         if sys.platform == "win32":
             return parse_windows_route(await _run(["route", "print", "-4" if v4 else "-6"]), family)
-    except (OSError, asyncio.TimeoutError, ValueError):
+    except Exception:
         return None
     return None

tests/test_gateway.py

@@ -1,3 +1,6 @@
+import asyncio
+import struct
+
 from hbd.client import gateway
 
 PROC_V4 = (
@@ -62,3 +65,11 @@ def test_windows_v4_lowest_metric():
 
 def test_windows_v6():
     assert gateway.parse_windows_route(WIN_V6, "ipv6") == "fe80::1"
+
+
+def test_default_gateway_never_raises_on_parser_error(monkeypatch):
+    """default_gateway catches all exceptions; never raises even if parser fails."""
+    monkeypatch.setattr("sys.platform", "linux")
+    monkeypatch.setattr(gateway, "parse_proc_route_v4", lambda _: (_ for _ in ()).throw(struct.error))
+    result = asyncio.run(gateway.default_gateway("ipv4"))
+    assert result is None