Ensure PPCIE verification exits non-zero on failure

[fallintoplace]

Summary

• Replace bare sys.exit() failure paths in PPCIE v1/v2 verification flows with typed exceptions
• Add explicit top-level handling in verification() to exit with status code 1 on PPCIE verification failures
• Preserve existing status updates while removing implicit-success exits

Notes

• This addresses security/CI misclassification where failure paths could return exit 0