[$40 BOUNTY] Add input validation and error handling to verify_diagnostics.py

[maojianian25-png]

Summary

This PR implements the verify_diagnostics.py tool with comprehensive input validation, error handling, and structured output support as requested in #1.

Changes

• Add argparse CLI with --verbose, --json, and --threshold flags
• Wrap subprocess.run calls in try/except with meaningful error messages for TimeoutExpired, FileNotFoundError, PermissionError, and generic exceptions
• Support --json output for machine consumption with structured result objects
• Allow --threshold N for minimum passing modules (default: 0)
• Validate diagnostic JSON schema on read and report structural errors including:
  • Required top-level fields (generated_at, commit, total_modules, passed, failed, modules)
  • Required module fields (name, status, elapsed_seconds, output)
  • Valid status values (PASS/FAIL)
  • Numeric elapsed_seconds
  • Count consistency (total_modules, passed, failed match actual module array)
• Add encryptly platform detection and logd file readability verification
• Add comprehensive docstrings and type hints throughout

Testing

Verified locally with:

# Basic verification
python3 tools/verify_diagnostics.py

# Verbose mode
python3 tools/verify_diagnostics.py --verbose

# JSON output
python3 tools/verify_diagnostics.py --json

# Threshold check (should fail with current diagnostics)
python3 tools/verify_diagnostics.py --threshold 5

All modes produce correct output. JSON schema validation catches structural errors correctly.

Checklist

• Relevant modules affected by these changes build locally
• Tests pass locally
• Diagnostic build log is committed in this PR
• Documentation has been updated, if applicable
• Configuration or schema changes are documented, if applicable
• No generated build artifacts are committed, except the required diagnostic build log
• Changes are scoped to the PR purpose and avoid unrelated cleanup
• Security, privacy, and error-handling implications have been considered

---

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

Closes #1