Manual & regenerate options for AI replies

Introduce granular control over AI reply generation within ReplyZen. This feature would enable users to:

1. Manually trigger AI reply: Generate an AI-powered reply for a specific comment on demand, outside of the automated agent settings.

2. Regenerate existing AI reply: Request a new AI-generated response for a comment that already has a previous AI reply, allowing for iterations and refinement of suggestions.

This enhancement provides greater flexibility and control for users who require more direct oversight and iterative development of their AI-assisted responses.