Parent Issue

Part of #1039

Problem

`git-operations.test.ts` tests clone, ls-remote, and config but not `git push` (the most important write operation in agentic workflows) or any authenticated git operation. Every production workflow uses authenticated git to push branches and create PRs.

Acceptance Criteria

• Add tests to `tests/integration/git-operations.test.ts` covering:
  • Authenticated `git clone` using a token (via `-e GITHUB_TOKEN=...`)
  • Authenticated `git push` through the proxy (clone a repo, create a branch, commit, push)
  • `git fetch` inside an existing clone
• The tests may need to create a temporary branch and clean up after. Use a test-specific branch name to avoid conflicts.
• Consider using the existing `gh-aw-firewall-test-*` repos for push testing if tokens are available, or skip if `GITHUB_TOKEN` is not set.

References

• `tests/integration/git-operations.test.ts`: Existing tests to extend
• The git-operations test file header mentions "Git with authentication" but no such test exists

Closes #1039 (when combined with other sub-issues)