Add safe library FIX evaluation and promotion

[rsasaki0109]

Summary

• pin gnssplusplus to merged safe library FIX implementation (81847eb)
• add WP174/WP175 evaluation, fault-injection, calibration, integrity, and promotion tooling
• add focused regression tests and the final promotion audit

Validation

• WP174/WP175 Python tests: 64 passed
• library C++ tests after upstream rebase: 844 total, 779 passed, 65 skipped, 0 failed
• Tokyo rebased smoke: 280/300 library FIX (93.3%), 0 observed false FIX, 0 lost epochs
• formal full routes: Tokyo 50.08%, Nagoya 66.02%, 0 observed false FIX
• final fault matrix: 64/64 recovered, 0 observed false FIX

Generated results, logs, and intermediate audit artifacts are intentionally excluded.