Retry Commits Generating request on invalid hunks

[sergeibbb]

Implement robust AI-assisted rebase generation with validation and retry logic

This solves #4395.

This piece of work introduces a new, robust workflow for generating AI-assisted rebases that organize code changes into logical commits. The changes add the generateRebase method, which now includes automatic retry logic: if the AI's response is missing hunks, includes extra hunks, or uses duplicates, the system will provide feedback and retry up to three times. The main workflow is broken into helper methods:

• sendRebaseRequestWithRetry orchestrates the retry loop and validation for AI responses.
• sendRebaseFirstAttempt handles the initial AI request and stores the conversation prompt for use in retries.
• validateRebaseResponse checks the AI's JSON output for correctness, ensuring all required hunks are present exactly once and no extras or duplicates exist. It also generates specific retry prompts to feed back to the AI if issues are found, using the dedent utility for clear formatting.

Detailed logging and error messages are added to make debugging easier. These changes ensure that AI-generated commit suggestions are always structurally correct, improving both reliability and reviewability of the tool's output.

Checklist

• I have followed the guidelines in the Contributing document
• My changes follow the coding style of this project
• My changes build without any errors or warnings
• My changes have been formatted and linted
• My changes include any required corresponding changes to the documentation (including CHANGELOG.md and README.md)
• My changes have been rebased and squashed to the minimal number (typically 1) of relevant commits
• My changes have a descriptive commit message with a short title, including a Fixes $XXX - or Closes #XXX - prefix to auto-close the issue that your PR addresses

[d13]

LGTM, branch just needs updating