- Add tracing-appender and tracing-journald for production logging
- Add LoggingConfig with trace_sample_rate, json_output, journald options
- Expand init_logging() with file rotation, journald, and stderr layers
- Add sanitize_path() helper for PII protection in logs
- Instrument FUSE operations with #[instrument] and trace decision points
- Instrument gRPC handlers (10 methods) with span correlation
- Add spawn instrumentation for health monitor, indexer, watcher tasks
- Add broadcast lag handling (RecvError::Lagged) in event subscribers
- Fix webhook.rs expect() calls with proper error handling
- Add logging to patterns.rs, collections.rs, artwork.rs database ops
- Add Drop impl logging for PluginManager and WatchHandle
- Update systemd service with rate limiting and journal output
- Add logrotate config and example config.toml with logging section
- Add CdcChunker using FastCDC v3 (16KB/64KB/256KB chunks)
- Add DeltaDetector with scan_origin() returning ScannedFile (no FileId assignment)
- Add OriginWatcher with inotify and 200ms debounce using tokio::spawn
- Fix LocalOrigin::read() to loop until all bytes read
- Add read_full() method to Origin trait
- Add mtime field to ChunkManifest
- Update ContentFetcher to use CDC chunking
- Update bandwidth reduction test to assert >90% (NFR-6.4)
Tests: 71 pass (+11 new)
- Add musicfs-cas crate: CasStore, ChunkHash, FileReader, ChunkManifest
- Add LruEviction policy to musicfs-cache for cache size management
- Integrate FileReader into FUSE filesystem for actual file reads
- Use xxHash64 for content hashing, sled for index, msgpack serialization
- Default cache path: ~/.cache/musicfs/chunks/ with 256 subdirs sharding
- 20 new tests (14 CAS unit + 3 integration + 3 eviction), 54 total