- safe_file: write policy documented (durable for what can't be recreated, atomic-only for
recreatable outputs); new write_atomic_nosync (temp + rename, temp removed on failure, no
file/folder sync); per-thread sync counter for tests.
- export::write_file (exports, renders, screenshots, merge previews, CLI/MCP) uses the
non-syncing writer; new write_file_durable keeps the sync for Edit a Copy (the TIFF becomes a
library photo). Catalog, sidecars, settings, DNG conversion/merges and smart previews stay
durable; the #93 original-overwrite guard is untouched.
- Import > Copy verifies the synced copy against the probe's content hash (SipHash-1-3/128 of the
whole file) instead of re-reading the source; byte compare when there is no hash. A file changed
since Review Import is now refused instead of imported with stale details. Move keeps its
byte-for-byte check before deleting sources.
- check_write_target: skip building the library-wide guard when nothing is at the target.
- write_new_unique keeps its read-back (DNGs replace raws; cheap next to encoding).
- Tests: no sync on the export path, durable writers still sync, Copy caught by the probe hash
(corrupt copy, stale hash, changed source); ignored timing test write_policy_timing.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>