# US04-03 — Apply and Verify Guarded Renames

Epic: [E04](../E04-guarded-renaming.md)

As a user, I want confirmed plans applied without overwrites so reorganizing the
library preserves identity and bytes.

## Acceptance criteria

- Apply requires current plan/version confirmation and an exclusive mutation lease.
- Preconditions are rechecked immediately before each mutation; unexpected targets
  are never overwritten.
- Case-only and cross-filesystem operations use safe staged procedures.
- Postconditions verify bytes and paths, update occurrences, and reconcile stable IDs.

## Automated tests

- Filesystem integration tests cover normal, case-only, collision, cross-filesystem,
  stale source, and repeated apply.
- Tests assert byte preservation and database/path consistency after restart.

## Dependencies

- US04-02