Adds the on-disk content and thumbnail cache keyed by fileID: originals/ and thumbnails/ under cacheDirectory, present-means-complete (streaming atomic rename), orphan temp reaping on open. Photo.original/thumbnail return a cached path with no network when present, else fetch through the shared request pool; thumbnails.ensure drives the thumbnail pool with priority, dedup and AbortSignal. One shared RequestPools set serves both the ML fetch and the content cache. Content-hash integrity is deferred (#68); authenticated streaming decrypt guarantees integrity now.
Model: opus-4-8
Library.open loads metadata.json and serves reads from RAM: an empty cache awaits the first refresh, an existing cache returns at once and refreshes in the background so an unreachable server never stalls open(). A background timer refreshes every refreshIntervalSeconds (default 3), diffing only changed albums via the resumable cursor+tombstone enumerators and rewriting metadata.json only when something changed. A refresh failure is invisible to reads and surfaced via status()/onProgress; a failed save keeps status().lastError set and retries until one lands, so a stale disk is never masked. No sync()/refresh()/serverReachable surface; status() and close() included.
Model: opus-4-8
Adds the metadata.json store: loads whole into RAM with id-lookup Maps, rewrites whole through the exported fsync atomic writer (temp, fsync, rename, dir fsync); a missing, unparseable, or wrong-schema file loads as empty (it is a cache); directory 0700, file 0600. No lock file, no public sync().
Model: opus-4-8