Fix Windows file artifact URI path normalization

Author: cyrus-mz

src/google/adk/artifacts/file_artifact_service.py

@@ -25,6 +25,7 @@
 from typing import Union
 from urllib.parse import unquote
 from urllib.parse import urlparse
+from urllib.request import url2pathname
 
 from google.genai import types
 from pydantic import alias_generators
@@ -59,7 +60,10 @@ def _file_uri_to_path(uri: str) -> Optional[Path]:
   parsed = urlparse(uri)
   if parsed.scheme != "file":
     return None
-  return Path(unquote(parsed.path))
+  path_str = unquote(parsed.path)
+  if os.name == "nt":
+    path_str = url2pathname(path_str)
+  return Path(path_str)
 
 
 _USER_NAMESPACE_PREFIX = "user:"

src/google/adk/cli/service_registry.py

@@ -73,6 +73,7 @@ def my_session_factory(uri: str, **kwargs):
 from typing import Protocol
 from urllib.parse import unquote
 from urllib.parse import urlparse
+from urllib.request import url2pathname
 
 from ..artifacts.base_artifact_service import BaseArtifactService
 from ..memory.base_memory_service import BaseMemoryService
@@ -293,7 +294,12 @@ def file_artifact_factory(uri: str, **_):
       )
     if not parsed_uri.path:
       raise ValueError("file:// artifact URIs must include a path component.")
-    artifact_path = Path(unquote(parsed_uri.path))
+    
+    artifact_path_str = unquote(parsed_uri.path)
+    if os.name == "nt":
+      artifact_path_str = url2pathname(artifact_path_str)
+    
+    artifact_path = Path(artifact_path_str)
     return FileArtifactService(root_dir=artifact_path)
 
   registry.register_artifact_service("memory", memory_artifact_factory)