Cache and Compaction
Implemented cache operations and configuration fields that do not run a compactor.
Lens::cache_stats() returns cache counters; clear_cache() drops cached blocks and does not remove persisted B-tree data. BlockCache/BlockPointer describe cached node lookup. Inspect cache declarations and block declarations for exact fields.
LensConfig declares cache_size, auto_compact, compact_threshold, snapshot_retention, enable_wal, sync_writes, order and max_batch_size. The current Lens implementation does not implement an automatic compaction worker or retention sweep from those compaction/retention flags. CompactionOptions is a configuration type, not a callable compaction operation. Do not promise storage reclamation, automatic snapshot expiry or an independent Lens WAL from setting these fields.
The implemented persistence path is Strand-backed node writes plus authoritative Lens root metadata publication. Follow key-value operations and snapshots for the supported behavior.
