[ BOUNTY] Add input validation and error handling to verify_diagnostics.py

[Xiaofei-Z]

Summary

Closes #1. Adds input validation, error recovery, and structured output to tools/verify_diagnostics.py.

Changes

• argparse CLI: --verbose/-v, --json/-j, --threshold/-t (default 0)
• Subprocess error recovery: run_build() wraps subprocess.run in try/except handling TimeoutExpired, FileNotFoundError, PermissionError, OSError with meaningful messages
• --json output: full machine-readable report (build status, diagnostics found, schema validity, threshold met, overall ok)
• --threshold N: exit non-zero if passing modules < N
• validate_diagnostic_json(): schema validation — checks required keys, type correctness (modules is list, passed/failed are int), reports structural errors clearly

Testing

• python3 tools/verify_diagnostics.py --help → shows all flags
• python3 tools/verify_diagnostics.py → runs build, validates diagnostics, reports PASS/FAIL
• python3 tools/verify_diagnostics.py --json → outputs structured JSON report
• python3 tools/verify_diagnostics.py --threshold 5 → threshold logic verified
• Reverse test: corrupting JSON → validator catches and reports structural error
• python3 build.py run; diagnostic artifacts present

Checklist

• argparse CLI with --verbose, --json, --threshold
• subprocess.run wrapped in try/except with meaningful errors
• --json output for machine consumption
• --threshold N for minimum passing modules (default 0)
• Diagnostic JSON schema validation with structural error reporting
• Existing behavior preserved when run without flags
• Changes scoped to tools/verify_diagnostics.py

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• I would like to request that my diagnostic build log is removed before merging

[Xiaofei-Z]

Hi @Andyyook, submitted this for the bounty. Added argparse CLI (--verbose/--json/--threshold), subprocess error recovery for all failure modes, JSON schema validation with structural error reporting, and threshold support. All acceptance criteria covered. Happy to address any feedback. Thanks!