feat: Phase 7b - Wire LockGuardedToolExecutor into tool runner

[roomote-v0]

Related GitHub Issue

Closes: #12330

Description

This PR attempts to address Issue #12330 by completing the Phase 7b integration -- wiring the LockGuardedToolExecutor (from PR #12352) into the actual tool dispatch flow.

What it includes:

1. Tool runner integration (presentAssistantMessage.ts):

   • Before each write tool executes, tryAcquireLocks() is called to acquire file locks
   • If a lock conflict is detected (another task holds the lock), an LLM-friendly error is returned via pushToolResult and the tool is skipped
   • Locks are released in a finally block after tool execution completes (success or failure)
   • Non-write tools (read_file, list_files, etc.) pass through without lock checks

2. Task dispose cleanup (Task.ts):

   • releaseAllLocks(taskId) is called in Task.dispose() to release any stale locks when a task is aborted or disposed
   • Prevents orphaned locks from blocking other tasks indefinitely

3. Singleton management (file-lock/index.ts):

   • getFileLockManager() and getLockGuardedToolExecutor() singleton getters for shared instances
   • resetFileLockSingletons() for test isolation

4. 14 integration tests covering:

   • Singleton lifecycle and identity
   • Lock acquisition/release around write tools
   • Cross-task conflict blocking and resolution
   • releaseAllLocks cleanup on dispose
   • Path extraction for all write tool types (write_to_file, apply_patch, edit_file, search_replace)

Stacked branching: main -> Phase 1 -> Phase 2+3 -> Phase 4+5+6 -> Phase 7a -> Phase 7b -> Phase 7b integration (this PR)

Re: Phase 7c (UI surfacing): Lock conflicts are currently returned to the LLM only. UI surfacing in the Background Tasks panel is planned for Phase 7c.

Feedback and guidance are welcome.

Test Procedure

• Run: cd src && npx vitest run services/file-lock/__tests__/
• All 79 tests pass (24 FileLockManager + 26 LockGuardedToolExecutor + 14 integration + 15 existing)

Pre-Submission Checklist

• Issue Linked: This PR is linked to an approved GitHub Issue.
• Scope: Changes are focused on wiring the lock executor into the tool runner.
• Self-Review: Performed thorough self-review.
• Testing: 14 new integration tests added.
• Contribution Guidelines: Read and agreed.

Interactively review PR in Roo Code Cloud

[roomote-v0]

Closing in favor of consolidated PR #12356 which merges all Phase 7 work into a single PR as requested.