chore(deps-dev): bump @vscode/vsce from 3.7.1 to 3.9.1 (#253)

Build tool upgrade. Verified locally: build OK, vsix packaging OK (8.73 MB, 675 files).

Author: dependabot[bot]

package-lock.json

@@ -181,7 +181,7 @@
   "devDependencies": {
     "@types/node": "^25.6.0",
     "@types/vscode": "=1.110.0",
-    "@vscode/vsce": "^3.7.1",
+    "@vscode/vsce": "^3.9.1",
     "esbuild": "^0.28.0",
     "esbuild-plugin-polyfill-node": "^0.3.0",
     "ts-node": "^10.9.2",