feat: add OAuth token authentication support (#236)

* feat: add OAuth token authentication support

Add claude_code_oauth_token as an alternative authentication method to anthropic_api_key.
This provides more flexibility for users who prefer OAuth authentication.

- Add claude_code_oauth_token input to action.yml
- Pass OAuth token through to claude-code-base-action
- Update README with OAuth token documentation and examples
- Update security best practices to cover both authentication methods
- Add OAuth example to examples/claude.yml

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

Co-Authored-By: Claude <noreply@anthropic.com>

* docs: add OAuth token generation instructions for Pro/Max users

Update README to mention that Pro and Max users can generate OAuth tokens
by running `claude setup-token` locally. This provides clearer guidance
for users who want to use OAuth authentication instead of API keys.

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

Co-Authored-By: Claude <noreply@anthropic.com>

* docs: update CI capabilities documentation

- Move GitHub Actions access from limitations to capabilities in README
- Update FAQ to explain how to enable CI/CD access with actions:read permission
- Clarify that Claude can access workflow results on PRs where it's tagged

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

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>

FAQ.md

@@ -51,14 +51,29 @@ allowed_tools: "Bash(git rebase:*)" # Use with caution
 
 Claude doesn't create PRs by default. Instead, it pushes commits to a branch and provides a link to a pre-filled PR submission page. This approach ensures your repository's branch protection rules are still adhered to and gives you final control over PR creation.
 
-### Why can't Claude run my tests or see CI results?
+### Can Claude see my GitHub Actions CI results?
 
-Claude cannot access GitHub Actions logs, test results, or other CI/CD outputs by default. It only has access to the repository files. If you need Claude to see test results, you can either:
+Yes! Claude can access GitHub Actions workflow runs, job logs, and test results on the PR where it's tagged. To enable this:
 
-1. Instruct Claude to run tests before making commits
-2. Copy and paste CI results into a comment for Claude to analyze
+1. Add `actions: read` permission to your workflow:
 
-This limitation exists for security reasons but may be reconsidered in the future based on user feedback.
+   ```yaml
+   permissions:
+     contents: write
+     pull-requests: write
+     issues: write
+     actions: read
+   ```
+
+2. Configure the action with additional permissions:
+   ```yaml
+   - uses: anthropics/claude-code-action@beta
+     with:
+       additional_permissions: |
+         actions: read
+   ```
+
+Claude will then be able to analyze CI failures and help debug workflow issues. For running tests locally before commits, you can still instruct Claude to do so in your request.
 
 ### Why does Claude only update one comment instead of creating new ones?