Implement musicfs-search crate with tantivy index and fuzzy queries

- SearchIndex with Arc<RwLock<IndexWriter>> pattern
- Fuzzy query support via custom term~N parsing
- Indexer with EventBus integration and MetadataLookup trait
- SearchQueryBuilder for programmatic query construction
- remove_by_path fallback for FileRemoved handling

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/claude-agent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

musicfs/crates/musicfs-search/Cargo.toml

@@ -4,3 +4,15 @@ version.workspace = true
 edition.workspace = true
 
 [dependencies]
+musicfs-core = { path = "../musicfs-core" }
+
+tantivy.workspace = true
+moka.workspace = true
+parking_lot.workspace = true
+tokio = { workspace = true, features = ["sync", "time"] }
+tracing.workspace = true
+thiserror.workspace = true
+
+[dev-dependencies]
+tempfile.workspace = true
+tokio = { workspace = true, features = ["rt-multi-thread", "macros"] }