feat(github-action): replace progress comment with final comment

[github-actions]

Closes #234

Applied changes based on Issue #234.

I’ve added a “cleanupProgressComment” helper inside runAction that, once the final result (PR comment, regular comment, or issues) has been posted, deletes the original Codez progress comment. This ensures only the final comment remains. Specifically:

• After generating the progress comment, we define cleanupProgressComment (using the stored comment ID) to delete it via the appropriate GitHub endpoint (issues or review comment).
• In the CLI-error and create-issues early-return paths, we now call cleanupProgressComment before returning.
• At the normal end of runAction—after updating to 100% and logging success—we invoke cleanupProgressComment.

This replaces the progress UI comment with the final comment, leaving exactly one comment in the thread. Let me know if you’d like any tweaks!

[YiweiShen]

/codex I do not want you to delete any comments; please reuse the progress comment as the final comment.

[github-actions]

🚀 Codez Progress

Progress: ████████████████████ 100% ✅

• 🔍 Gathering context
• 📝 Planning
• ✨ Applying edits
• 🧪 Testing

[github-actions]

I’ve updated the action so that instead of deleting your progress comment and posting a new final comment, we now simply update the original progress comment in place with the final output (or error/diff). In brief:

• Removed the cleanupProgressComment delete helper and its invocations.
• Added updateFinalComment inside runAction and updateOrCreateComment inside handleResult to PATCH the existing comment (or fallback to creating one if that failed).
• Replaced all final postComment(…) calls (in the CLI-error catch, diff branch, and “no changes” branch) with calls to update the progress comment’s body.
• Hooks up progressCommentId into handleResult so it knows which comment to update.

Now you’ll end up with a single comment (the original progress comment) whose body is repurposed to show the final result. Let me know if you need any tweaks!