Feat: Enhance trigger configuration with granular controls and concurrency management

[HungKNguyen]

Summary

Adds fine-grained trigger controls and concurrency management to the code review action, giving users better control over when reviews run and preventing duplicate/wasteful reviews.

Key Changes

Trigger Configuration

• New trigger inputs for granular control:
  • trigger-on-open - Run on PR open/reopen (default: true)
  • trigger-on-commit - Run on every commit (default: false)
  • trigger-on-review-request - Run when review requested (default: true)
  • trigger-on-mention - Run when bot mentioned in comments (default: true)
• Deprecated run-every-commit in favor of new trigger-on-commit option
• Bot mention support - Automatically detects and responds to @bot-name in PR comments
• Review appeal workflow - Developers can request re-review on same commit via GitHub's review request feature

Concurrency Control

• Added concurrency group to prevent simultaneous runs on same PR
• Cancels in-progress runs when new commits arrive
• Reduces API costs by preventing duplicate reviews

Filtering Configuration

• New inputs for filtering control:
  • enable-heuristic-filtering - Pattern-based filtering (default: true)
  • enable-claude-filtering - Claude API validation (default: false)
• Made heuristic filtering optional and configurable

Implementation Details

• Refactored enablement logic into scripts/determine-claudecode-enablement.sh
• Added support for issue_comment events to handle bot mentions
• Auto-detects bot identity (works with both github-actions[bot] and custom GitHub Apps)
• Updated workflow to handle both pull_request and issue_comment events
• Comprehensive README documentation with usage examples

Test Plan

• All existing Python tests pass (177 tests)
• Added bash script tests for enablement logic
• JavaScript tests pass

Backwards Compatibility

All changes are backwards compatible:

• Existing workflows continue to work with default behavior
• run-every-commit still works but shows deprecation warning
• Default trigger behavior matches previous functionality (review on open + explicit requests)

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This PR focuses on the configuration enhancements and trigger mechanism improvements based on the commit message "enhance configuration and trigger" and the extensive changes to trigger logic,
filtering options, and concurrency control.

[github-actions]

Found 4 correctness and reliability issues. Consider addressing the suggestions in the comments.