feat: add option to pause file-watching after initial indexing

[roomote]

Related GitHub Issue

Closes: #8131

Description

This PR attempts to address Issue #8131, specifically the concern raised by @Jerrill about CPU-expensive file-watching operations when using multiple VSCode instances with git worktrees.

Key implementation details:

1. New workspace-scoped setting: Added roo-cline.codeIndex.fileWatchingEnabled (default: true) with "scope": "resource" so each workspace/worktree can have independent settings.

2. New IndexedPaused state: Added to the indexing state machine to distinguish between "Indexed with active watcher" and "Indexed without watcher".

3. Conditional watcher start: Modified the orchestrator to check isFileWatchingEnabled after initial indexing completes. If disabled, the state transitions to IndexedPaused instead of starting the file watcher.

4. Worktree support: Since each worktree is opened as a separate workspace in VSCode, and CodeIndexManager uses workspace-path-based singletons, each worktree gets its own independent CodeIndexManager instance with its own settings.

Usage for users with multiple worktrees:

• Run initial indexing in each worktree to populate the search index
• Set roo-cline.codeIndex.fileWatchingEnabled: false in worktrees where you want to reduce CPU usage
• The codebase_search tool will still work using the existing index
• Re-run indexing manually when significant changes occur in paused worktrees

Test Procedure

1. Unit tests: Added comprehensive tests in src/services/code-index/__tests__/file-watching-pause.spec.ts covering:

   • File watcher is NOT started when setting is disabled
   • File watcher IS started when setting is enabled (default)
   • State transitions to IndexedPaused when file watching is disabled
   • State transitions to Indexed when file watching is enabled
   • Re-indexing works from IndexedPaused state
   • Manager exposes isFileWatchingEnabled getter
   • IndexedPaused state has a default message
   • ConfigManager returns true by default when setting is not configured

2. Run tests: cd src && npx vitest run services/code-index/__tests__/file-watching-pause.spec.ts

3. Manual testing: Open workspace settings and toggle roo-cline.codeIndex.fileWatchingEnabled, then trigger indexing to observe state changes.

Pre-Submission Checklist

• Issue Linked: This PR is linked to an approved GitHub Issue (see "Related GitHub Issue" above).
• Scope: My changes are focused on the linked issue (one major feature/fix per PR).
• Self-Review: I have performed a thorough self-review of my code.
• Testing: New and/or updated tests have been added to cover my changes (if applicable).
• Documentation Impact: I have considered if my changes require documentation updates (see "Documentation Updates" section below).
• Contribution Guidelines: I have read and agree to the Contributor Guidelines.

Screenshots / Videos

N/A - This is a backend feature with no UI changes.

Documentation Updates

• Yes, documentation updates are required. The new setting roo-cline.codeIndex.fileWatchingEnabled should be documented, explaining its purpose for reducing CPU usage with multiple worktrees/instances.

Additional Notes

This PR addresses @Jerrill's question in issue #8131:

Is there a way to enable an initial indexing to support codebase_search, but pause file-watching, which is a very CPU expensive operation when there is one instance much less multiples?

Feedback and guidance are welcome!

Get in Touch

N/A - Automated contribution

[roomote]

Rooviewer   See task on Roo Cloud

Review completed. The implementation correctly adds a workspace-scoped setting to pause file-watching after initial indexing. One minor consistency issue was identified:

• Use i18n translation keys for new IndexedPaused state messages in orchestrator.ts to match the existing code pattern

_{Mention @roomote in a comment to request specific changes to this pull request or fix all unresolved issues.}

[roomote]

This message uses a hardcoded string while the existing code pattern (e.g., line 202) uses the t() function for i18n translations. For consistency and to support non-English locales, consider adding translation keys for these new messages.

_{Fix it with Roo Code or mention @roomote and request a fix.}