feat: Implement interactive AI-assisted pull request reviews

[finxo]

Pull Request

📝 Summary

This pull request introduces a comprehensive, interactive workflow for reviewing pull requests directly from the command line. It enables users to fetch PRs, view diffs with full context, read and write review comments, and leverage AI to automatically generate and apply code suggestions. This feature aims to significantly streamline the code review process by integrating it deeply into the developer's terminal-based workflow.

🔧 Changes Made

• New PR Review Workflow: Implemented a new multi-step interactive workflow for conducting code reviews.
• AI-Powered Code Fixing: Introduced a feature to generate AI-based code fixes for review comments. This uses Git worktrees to safely preview and apply changes.
• Enhanced Commenting System:
  • Overhauled comment fetching to use the GitHub GraphQL API, enabling support for full review threads and replies.
  • Implemented a staging area for review comments, allowing users to draft, edit, and queue replies before submitting them as a single review.
  • Added a visual indicator for comments that are on outdated parts of the diff.
• Advanced Diff and UI Rendering:
  • Implemented GitHub-style diff rendering, including side-by-side line numbers and intelligent context around comment locations.
  • Decomposed the main review step into modular UI components and action helpers for improved maintainability.
  • Refactored comment widgets, moving them from the core UI to the GitHub plugin.
• Architectural Refactoring:
  • Extracted GitHub-specific business logic into dedicated operation modules (e.g., for comments, reviews).
  • Simplified and consolidated logic for diff context calculation and comment parsing into shared utilities.
• Documentation: Updated the TUI developer documentation (textual.md) to reflect the new UI components, widgets, and best practices introduced.

🧪 Testing

• Unit tests added/updated
• Integration tests added/updated
• Manual testing performed
• All tests passing

✅ Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published