fix: resolve generic types in _python_type_to_json

Use origin type for type_map lookup so list[str] -> "array",
dict[str, int] -> "object", etc. instead of falling back to "string".

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: kingpanther13

src/ha_mcp/tools/tool_proxy.py

@@ -255,7 +255,7 @@ def _python_type_to_json(python_type: Any) -> str:
         dict: "object",
         list: "array",
     }
-    return type_map.get(python_type, "string")
+    return type_map.get(origin or python_type, "string")
 
 
 def discover_proxy_tools(