Expand description
Disk-backed structural graph cache with versioned postcard encoding, fs2 per-shard locking, atomic writes via NamedTempFile::persist, and size-capped LRU eviction by file mtime. All I/O errors degrade silently via tracing::warn!.
GraphDiskStore itself and its public API compile on every target,
including wasm32-unknown-unknown, so callers never need their own
cfg gates. Only the actual disk I/O (which depends on fs2 and
tempfile, neither WASM-safe) is gated: on wasm32, get always misses
and put is a no-op, matching aptu’s cache.rs WASM stub pattern.