fix(ci): add write permissions for changesets action

The changesets action needs explicit permissions to:
- contents: write - to push commits and create branches
- pull-requests: write - to create/update release PRs

Without these, github-actions[bot] gets 403 permission denied.

Author: Mohammod Al Amin Ashik

.github/workflows/release.yml

@@ -18,6 +18,9 @@ jobs:
   # ─────────────────────────────────────────────────────────────
   changesets:
     runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
     outputs:
       published: ${{ steps.changesets.outputs.published }}
       publishedPackages: ${{ steps.changesets.outputs.publishedPackages }}