lire1131/dsh-undo-savepoint

## Core Features
- The plugin records snapshots of DSH startup-critical configuration files and user plugin code trees, supporting undo, redo, and restoration to any saved version through WebUI, chat, or offline CLI entry points.
- Snapshot creation can be triggered automatically after configuration or plugin changes, manually from the panel or CLI, and restored versions can optionally rebuild dependencies using pnpm install when package manifests or lockfiles are affected.
- Sensitive values in .env and credential files are masked in snapshot exports while real values remain in a local vault, allowing local rollback to restore complete data without exposing secrets in exported ZIP files.
- A safe mode disables all plugins except the undo system when DSH cannot start, creates an automatic snapshot and configuration backup, and supports one-click exit with profile and home-level patch backup handling.
- Offline recovery tools include a GUI window, PowerShell CLI commands, and a desktop shortcut creation script, providing access to undo, restore, safe mode, crash banners, and rollback logs when DSH is not running.

## Use Cases
- When a configuration change or plugin modification prevents DSH from starting, the safe mode entry or offline manager can restore a previous state and restart the environment.
- When a user plugin code tree is broken by edits, including yield* code accidents, a snapshot can restore the affected files without requiring manual reinstallation or session loss.
- When moving snapshots between machines, the export and import ZIP workflow and pre-restore missing-plugin checks identify dependencies before restoration proceeds.

## Technical Details
- The host plugin loads @deepseek-ai/dsh-tools through createRequire from the DSH installation root, with DSH_ROOT available as an override, avoiding repository-local dependency installation.
- Snapshot storage separates manual and automatic libraries under a configurable root, retains the most recent 20 automatic entries, and migrates legacy flat layouts into the newer structure at startup.
- Multi-profile support derives the active profile from DSH startup arguments, isolates snapshot repositories by profile, and allows offline tools to use DSH_UNDO_PROFILE or settings-based profile names.
- A REST API exposes status, list, settings, undo, redo, restore, remove, snapshot, and directory-picker endpoints for the WebUI, with optional dependency synchronization flags for restore operations.

## Notes
- The plugin requires an installed DSH environment and Node.js 20 or later, and local installation instructions include GitHub plugin addition or manual cloning with a junction and patch-file mount.
- Snapshots include configuration copies that may contain secrets, so snapshot directories and exports should not be shared externally even though exports mask sensitive values.
- Snapshot size is limited to 5 MB per referenced snapshot, and oversized plugin code trees are marked as truncated manifests, with