New File System Change Tracking, Enhanced Super Diff

[bassamsdata]

Description

Prerequisite: PR #2219

3 new/refactored changes in this PR:

1. New FS Monitor to track all chnages made by LLM to the files.
2. New UI for SuperDiff.

Details:

This replaces the old snapshot-based edit_tracker with FSMonitor, an event-driven file system monitor.

FSMonitor uses OS-level file events (vim.uv.new_fs_event) and async I/O to reliably detect created, modified, deleted, and renamed files.

It keeps a content cache for efficient diffing, debounces rapid events, and exposes APIs to start/stop watches, tag changes by tool execution time ranges, and retrieve change lists or stats.

What this fixes and benefits:

• Race conditions and unreliable diffs from snapshot comparisons.
• Inability to detect file creation, deletion, and renames.
• Blocking or slow I/O due to synchronous reads.
• Easier to extend (e.g., restore checkpoints) and to integrate with ACP, HTTP, or future adapters and strategies or external tools.
• Way more cleaner API suitable for broader plugin ecosystem/extensions

Note:
this is still work in progress.

Thank you

Related Issue(s)

Screenshots

Checklist

• I've read the contributing guidelines and have adhered to them in this PR
• I've added test coverage for this fix/feature
• I've run make all to ensure docs are generated, tests pass and my formatting is applied
• (optional) I've updated CodeCompanion.has in the init.lua file for my new feature
• (optional) I've updated the README and/or relevant docs pages