Add comprehensive logging with tracing, file rotation, and systemd integration

- 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

musicfs/crates/musicfs-cache/src/db.rs

@@ -16,7 +16,7 @@ pub struct Database {
 
 impl Database {
     pub fn open(path: &Path) -> Result<Self> {
-        info!(?path, "Opening database");
+        debug!(?path, "Opening database");
 
         let conn =
             Connection::open(path).map_err(|e| Error::Database(format!("open failed: {}", e)))?;
@@ -24,9 +24,12 @@ impl Database {
         conn.execute_batch(SCHEMA)
             .map_err(|e| Error::Database(format!("schema init failed: {}", e)))?;
 
-        Ok(Self {
+        let db = Self {
             conn: Arc::new(Mutex::new(conn)),
-        })
+        };
+        let count = db.file_count().unwrap_or(0);
+        info!(path = ?path, file_count = count, "Database opened");
+        Ok(db)
     }
 
     pub fn open_memory() -> Result<Self> {