fix(ci): pin dependencies to resolve supply-chain policy violations

- Added pnpm overrides in root package.json to pin '@types/node', 'undici', 'electron-to-chromium', and '@csstools/css-syntax-patches-for-csstree' to versions satisfying the minimum release age policy.
- Regenerated pnpm-lock.yaml with policy-compliant versions.

package.json

@@ -0,0 +1,12 @@
+{
+  "name": "baron-sso-root",
+  "private": true,
+  "pnpm": {
+    "overrides": {
+      "@types/node": "24.12.4",
+      "undici": "7.26.0",
+      "electron-to-chromium": "1.5.360",
+      "@csstools/css-syntax-patches-for-csstree": "1.1.4"
+    }
+  }
+}