[ScaleLeanChris]

Summary

Enforces assignment and linked-evidence write authority at shared server boundaries. Preserves dedicated lifecycle operations, legacy aliases, and ordinary shared-record workflows. Adds an authority table through schema migration 3 → 4.

Verification

• Local live service was patched and verified before publication; forbidden generic assignment write returned 403-equivalent and the record revision stayed unchanged.
• 85 repository tests and 39 Hermes-plugin tests passed independently.
• Production build and isolated multi-file backup, upgrade, restore, and rollback rehearsal passed.
• Seven company databases upgraded to schema 4; local health, web, and unauthenticated denial probes passed.

Release note

Schema-3 servers cannot read upgraded company files. Rollback needs a consistent pre-upgrade backup and loses writes after that snapshot. Existing evidence is not retroactively repaired. Review residual legacy conflicts before editing those records.

This PR makes the now-live local fix durable upstream; it does not introduce additional service changes.