fix: also convert --import resolver path to file URL for Windows

The spawnSync --import flag also receives a bare Windows path.
Convert it with pathToFileURL like the script import.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/resources/extensions/gsd/tests/verification-gate.test.ts

@@ -269,7 +269,7 @@ test("verification-gate: no DEP0190 deprecation warning when running commands",
       [
         "--throw-deprecation",
         "--experimental-strip-types",
-        "--import", resolverPath,
+        "--import", pathToFileURL(resolverPath).href,
         "--input-type=module",
         "-e", script,
       ],