[fix] python coder tool signal

[IsaacGHX]

⚡️ Fix: Thread-Safe Python Execution

Description:
Replaced signal.alarm with threading to handle code execution timeouts.

Changes:

• Executor: Wraps exec() in a daemon thread. Uses thread.join(timeout) to enforce limits.
• Tool: Updates timeout context manager to use threading.Timer (cross-platform compatible).

Benefits:

• Fixes signal only works in main thread error in multi-threaded training loops.
• Prevents tool execution from blocking or crashing the main application loop.