feat: implement all 6 frailbox bounty challenges

[aldorizona10-glitch]

Summary

Implements all 6 bounty challenges in one PR.

Issue #1: Python secrets validation (tools/config_generator.py)

• Added PRODUCTION_REQUIRED_SECRETS and PLACEHOLDER_PATTERNS constants
• Added validate_production_secrets() function with 6 test cases
• Added --validate-production CLI flag
• Fixed SENSITIVE_KEYS dedup

Issue #2: Rust SARIF export (tools/ai_reviewer.py)

• Added redact_secrets() function for secret detection/redaction
• Added to_sarif() function converting findings to SARIF JSON
• Added --sarif-output CLI flag
• 3 inline tests covering clean, secret, and failing findings

Issue #3: C logger retention report (frailbox/retention_report.c/.h)

• Added LogFileInfo struct and generate_retention_report() function
• Added print_retention_report() for human-readable output
• Added test_retention.c with 6 test cases

Issue #4: C newline regression (frailbox/test_newline_boundary.c)

• 16 test cases covering no trailing newline, single/multiple trailing newlines
• Tests for partial writes, ring buffer overflow, log level filtering
• Self-contained mock logger (no real I/O)

Issue #5: C self-test JSON (frailbox/selftest_json.c/.h)

• Added TestResult, TestSummary, TestCase structs
• Added run_selftest_json() with JSON output option
• Added test_selftest_json.c with 5 test cases

Issue #6: Perl watchdog JSON (v2/scripts/log_watchdog.pl)

• Added malformed JSON detection and counting
• Added --json-summary flag for JSON output
• Added --run-tests flag with 4 test suites
• Updated docs/OPERATIONS.md

Validation

• All C tests pass: test_newline_boundary (16/16), test_retention (6/6), test_selftest_json (5/5)
• build.py diagnostic artifact included
• PR template used as requested

[Soengkit]

Closing this PR because the linked fork issue is only a closed payout tracker for an already submitted upstream PR. This fork is not an active bounty intake or payment authority, and it is not accepting external submissions or payment details here.