Revert Messages

[mik-tf]

Summary

• Allows users to edit their previous messages in the chat interface with seamless AI retriggering.
• Works like modern AI chat applications, providing a smooth editing experience without conversation artifacts.
• Fixes Enable Revert to Previous Command / Edit a previous command #9

Key Changes

** Core Edit Functionality**

• Added editMessage() function in ChatInterface.svelte that enables inline editing of user messages
• Integrated with existing ChatMessage.svelte component for edit UI (textarea, save/cancel buttons, keyboard shortcuts)

** AI Retriggering Logic**

• When editing a user message followed by an AI response, automatically removes the old AI response and generates a fresh one
• Prevents duplicate messages by sending edited content directly to backend without creating new user message entries
• Maintains proper conversation flow and chronological ordering

[mik-tf]

Converting to draft and will make another PR without conflict.