feat: implement process isolation for JavaScript execution to prevent hangs

[my-local-agent]

Summary

This PR addresses issue xpert-ai#234 by implementing true process isolation for JavaScript code execution, preventing indefinite hangs from affecting the main process. Instead of adding a timeout parameter (which is a band-aid solution), this approach provides robust process-level protection.

Problem

The current implementation executes JavaScript code directly in the main process using isolated-vm. This has several issues:

1. No reliable timeout: isolated-vm's timeout parameter doesn't work in all scenarios (e.g., when waiting for promises)
2. Process vulnerability: Hanging code can block the entire main process
3. Inconsistent architecture: Python execution already uses process isolation, but JavaScript doesn't

Solution

Created a dedicated worker process (js-worker.js) that:

• Runs isolated-vm code in a separate process
• Communicates via stdin/stdout
• Can be forcefully terminated with SIGKILL on timeout
• Provides the same architecture as Python execution

Changes

New Files

• packages/server-ai/src/sandbox/commands/handlers/js-worker.js: Worker process for isolated JavaScript execution
• packages/server-ai/src/sandbox/commands/handlers/vm.handler.spec.ts: Unit tests for the new implementation

Modified Files

• packages/server-ai/src/sandbox/commands/handlers/vm.handler.ts: Refactored to use worker process instead of direct execution
• packages/server-ai/project.json: Added .js worker files to build assets

Key Benefits

✅ True Process Isolation: Code crashes/hangs won't affect the main process
✅ Reliable Timeout: Worker process can be killed anytime (5-second timeout, consistent with Python)
✅ Memory Protection: Worker has separate memory space with 128MB limit
✅ Consistent Architecture: Matches Python execution pattern
✅ No Breaking Changes: Maintains the same API interface

Testing

• Added comprehensive unit tests covering:
  • Simple code execution
  • Complex return values
  • Empty parameters
  • Syntax and runtime error handling
  • Timeout scenarios (infinite loops)

Notes

The worker includes robust module resolution to find isolated-vm in various build environments, ensuring compatibility with different deployment setups.

Fixes xpert-ai#234