feat: implement daemon mode for automatic file re-indexing

Adds a complete daemon mode that watches for file changes and
automatically re-indexes modified files using upsert semantics.

Key components:
- WatchDaemon with start/stop lifecycle and signal handling
- WatchSession connecting FileSystemWatcher with ProjectIndexer
- HealthMonitor with circuit breaker pattern for SurrealDB resilience
- PID file management for daemon lifecycle
- Full index_single_file() pipeline with embeddings and edge handling
- CLI commands: codegraph daemon start/stop/status

Also fixes pre-existing issues in codegraph-parser experimental feature:
- Lifetime issues in watcher.rs with tokio::spawn
- Variable naming in semantic.rs
- Type annotations in diff.rs

Author: jruokola

Cargo.lock

@@ -47,6 +47,9 @@ regex = { workspace = true }
 rayon = { workspace = true }
 num_cpus = { workspace = true }
 
+# Pattern matching for daemon mode
+glob-match = "0.2"
+
 # Internal dependencies
 codegraph-core = { workspace = true }
 codegraph-parser = { workspace = true }
@@ -83,6 +86,7 @@ path = "src/bin/codegraph-official.rs"
 
 [features]
 default = []
+daemon = ["codegraph-parser/watcher-experimental"]
 embeddings = ["dep:codegraph-vector", "codegraph-vector/lmstudio-reranker"]
 embeddings-local = ["embeddings", "codegraph-vector/local-embeddings"]
 embeddings-openai = ["embeddings", "codegraph-vector/openai"]