Add Prompt Management System

[avirajsingh7]

Implement core functionality for managing AI prompts with versioning and lifecycle controls. This system will allow safe experimentation, version tracking, rollback, and clean separation of staging vs. production-ready prompts.

Core Features to Implement

Prompt

• A named entity grouping multiple prompt versions.
• Example: summarize_email, generate_title, etc.

Prompt Version Stores:

• Prompt content (text instruction).
• Auto-incremented version number.
• Commit message.
• All versions are immutable.
• Soft-delete support (to hide obsolete versions).

Behavior and Constraints

• Creating a new version is the only way to make changes.
• No edits to existing versions (enforces auditability).
• Soft-deletion allows cleanup without permanent data loss.
• Rollback = re-promote an earlier version to production.