fix: support frozen sandbox worker entry

[F16shen]

Summary

• route frozen sandbox worker launches through an internal daemon entrypoint instead of sys.executable -m ...
• keep source runs on the existing module entrypoint and include aish.security.sandbox_worker in the PyInstaller sandbox binary
• add regression coverage for source and frozen worker launch paths

Problem

PyInstaller-built aish-sandbox binaries use the daemon executable as sys.executable. Launching the worker with sys.executable -m aish.security.sandbox_worker causes the daemon CLI to parse -m as its own argument and fail.

Testing

• /home/lixin/workspace/aish/.venv/bin/python -m pytest tests/security/sandbox/test_daemon_isolation.py tests/security/sandbox/test_sandboxd.py tests/security/sandbox/test_worker.py