fix(ci): add contents write permissions for docs and performance jobs

- Add contents: write to docs job for GitHub Pages deployment to gh-pages branch
- Add contents: write to performance job for benchmark data storage to gh-pages branch
- Fixes permission denied errors when pushing to repository
- Maintains security with minimal required permissions for each job function

Fixes run #16209410222 failures.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: starbops

.github/workflows/ci.yml

@@ -183,7 +183,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event_name == 'push' && github.ref == 'refs/heads/main'
     permissions:
-      contents: read
+      contents: write   # Required for pushing to gh-pages branch
       pages: write      # Required for GitHub Pages deployment
       id-token: write   # Required for GitHub Pages deployment
 
@@ -230,7 +230,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event_name == 'push' && github.ref == 'refs/heads/main'
     permissions:
-      contents: read
+      contents: write   # Required for pushing benchmark data to gh-pages
       actions: write    # Required for benchmark action auto-push
       pull-requests: write  # Required for benchmark action comments