* fix: Solving the problem of "make dev" failing to start in Windows environment
* fix: revert the change to the startup_config and fix the lint errors
* fix: Address Copilot review feedback
- Validate wait-for-port input and avoid PowerShell port interpolation
- Require Python 3 in serve.sh launcher detection
- Keep Windows event loop policy setup in sitecustomize only
- Clarify sitecustomize process-wide backend behavior