fix: persist strict runner annualization metadata

[Pigbibi]

Summary

• Add the XSHG calendar and 252-period annualization metadata to strict runner results.
• Cover persistence, readback, same-contract comparison, and legacy incomparability with a synthetic regression.

Validation

• Locked focused regression: passed.
• Full strict runner suite with the repository test import path: 33 passed.
• Bare pytest invocation has two pre-existing scripts import errors; CI config sets PYTHONPATH=src.
• git diff --check passed.

No UES #516 changes.