fix(gateway): harden StreamingConfig bool and numeric coercion

gateway/config.py

@@ -36,6 +36,26 @@ def _coerce_bool(value: Any, default: bool = True) -> bool:
     return is_truthy_value(value, default=default)
 
 
+def _coerce_float(value: Any, default: float) -> float:
+    """Coerce numeric config values, falling back on malformed input."""
+    if value is None:
+        return default
+    try:
+        return float(value)
+    except (TypeError, ValueError):
+        return default
+
+
+def _coerce_int(value: Any, default: int) -> int:
+    """Coerce integer config values, falling back on malformed input."""
+    if value is None:
+        return default
+    try:
+        return int(value)
+    except (TypeError, ValueError):
+        return default
+
+
 def _normalize_unauthorized_dm_behavior(value: Any, default: str = "pair") -> str:
     """Normalize unauthorized DM behavior to a supported value."""
     if isinstance(value, str):
@@ -220,13 +240,13 @@ def from_dict(cls, data: Dict[str, Any]) -> "StreamingConfig":
         if not data:
             return cls()
         return cls(
-            enabled=data.get("enabled", False),
+            enabled=_coerce_bool(data.get("enabled"), False),
             transport=data.get("transport", "edit"),
-            edit_interval=float(data.get("edit_interval", 1.0)),
-            buffer_threshold=int(data.get("buffer_threshold", 40)),
+            edit_interval=_coerce_float(data.get("edit_interval"), 1.0),
+            buffer_threshold=_coerce_int(data.get("buffer_threshold"), 40),
             cursor=data.get("cursor", " ▉"),
-            fresh_final_after_seconds=float(
-                data.get("fresh_final_after_seconds", 60.0)
+            fresh_final_after_seconds=_coerce_float(
+                data.get("fresh_final_after_seconds"), 60.0
             ),
         )
 

tests/gateway/test_config.py

@@ -9,6 +9,7 @@
     Platform,
     PlatformConfig,
     SessionResetPolicy,
+    StreamingConfig,
     _apply_env_overrides,
     load_gateway_config,
 )
@@ -149,6 +150,24 @@ def test_from_dict_coerces_quoted_false_notify(self):
         assert restored.notify is False
 
 
+class TestStreamingConfig:
+    def test_from_dict_coerces_quoted_false_enabled(self):
+        restored = StreamingConfig.from_dict({"enabled": "false"})
+        assert restored.enabled is False
+
+    def test_from_dict_malformed_numeric_values_fall_back_to_defaults(self):
+        restored = StreamingConfig.from_dict(
+            {
+                "edit_interval": "oops",
+                "buffer_threshold": "oops",
+                "fresh_final_after_seconds": "oops",
+            }
+        )
+        assert restored.edit_interval == 1.0
+        assert restored.buffer_threshold == 40
+        assert restored.fresh_final_after_seconds == 60.0
+
+
 class TestGatewayConfigRoundtrip:
     def test_full_roundtrip(self):
         config = GatewayConfig(