Two cleanups bundled because they're both single-line, post-MR-686
hygiene flagged by cubic during PR review:
- docs/server.md:102 said "Rate limiting — none" while the new
admission-control section earlier in the file documents 429s on the
five mutating handlers. Replace with a pointer to the admission
section and clarify that no graph-wide rate limiter is wired.
- schema_apply.rs:445-451 called `db.version().await` twice — once
for the conditional check, once in the error format string —
creating a cosmetic TOCTOU under interior mutability. Cache the
result in `current_manifest_version` so the error message reflects
the version that triggered the rejection.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
6ef07386d3