feat: enhance workflow with pre-commit hooks

[moris88]

This commit introduces several significant enhancements to the git-commit-helper-it tool, focusing on improving the AI-driven workflow, adding flexibility, and enhancing the overall user experience.

Key changes include:

• AI-Powered Commit Body Generation: The tool can now generate a detailed commit body in addition to the subject, providing a more comprehensive commit message based on the staged changes. This addresses the "why" behind the changes, not just the "what".
• AI-Powered Branch Naming Suggestions: When a user is on a protected branch (e.g., main, master), the tool will now suggest a descriptive branch name using AI, promoting consistent branch naming conventions and streamlining the process of creating new feature branches.
• Non-Interactive Mode (-y / --yes): A new -y or --yes flag has been added, allowing users to automatically accept all AI suggestions and prompts. This is particularly useful for scripting, CI/CD pipelines, or users who prefer a quicker, automated workflow.
• Configurable Pre-Commit Hooks: Users can now define custom shell commands (e.g., npm run lint, npm test) in the gch.config.json file. These commands will run automatically before the AI code review, ensuring code quality and test coverage before a commit is finalized. If any command fails, the commit process is aborted.
• Improved Branch Protection Flow:
  • The checkBranchAndMaybeCreateNew function now accepts the autoConfirm flag, allowing automated branch creation in non-interactive mode.
  • If no changes are detected, a more informative message is displayed when the AI cannot suggest a branch name.
• Flexible Configuration:
  • The init-config.cjs template has been updated to include new default settings for aiReviewEnabled (true by default) and preCommitCommands.
  • The geminiModel default has been updated from gemini-2.5-flash to gemini-1.5-flash for potentially better performance/cost balance.
• Enhanced Commit Message Handling:
  • The git.js commit function now uses a temporary file to pass the commit message to Git, which correctly handles complex messages (including multi-line bodies) and special characters, preventing command line parsing issues.
  • The getDiff function now accepts a cached parameter, allowing the retrieval of either staged or unstaged diffs as needed for different AI features (e.g., staged for commit message, unstaged for branch name suggestion).
• Documentation Updates: The README.md (English and Italian) has been thoroughly updated to reflect all new features, configurations, and usage instructions, including the new command-line options and workflow steps. This ensures users are fully aware of the tool's capabilities.
• Localization: New strings have been added to en.json and it.json to support the new features, such as messages for running pre-commit hooks, branch name suggestions, and commit body generation.

These changes collectively make the git-commit-helper-it tool more powerful, versatile, and user-friendly, catering to a wider range of developer workflows and automation needs.