fix: restore Kubernetes operator verification baseline

[josedab]

Summary

• Restores strict validation, auxiliary task shutdown, integration gating, and truthful Rust 1.88 MSRV metadata.
• Preserves repository public contracts while restoring or strengthening the verification baseline.
• Includes an AUDIT.md where the repository reached the audit/refactor phase.

Commits

• 62ddb4a fix(operator): restore complete verification baseline
• d9c3f82 docs(operator): record clean-code audit
• c99db76 fix(operator): align declared Rust MSRV
• 6fcf903 fix(operator): raise MSRV for resolved dependencies

Validation

Rust 1.88 fmt/strict Clippy/108 tests pass; live network tests remain explicitly ignored.

Known blockers / deferred work

• None beyond required PR checks and documented AUDIT.md deferrals.

Merge readiness

Ready for review. Merge only after all required GitHub checks and reviewer approvals pass.