fix: replace std::sync::Mutex with parking_lot::Mutex (#350)

Merges #422

src/onboard/wizard.rs

@@ -272,6 +272,12 @@ fn memory_config_defaults_for_backend(backend: &str) -> MemoryConfig {
             0
         },
         chunk_max_tokens: 512,
+        response_cache_enabled: false,
+        response_cache_ttl_minutes: 60,
+        response_cache_max_entries: 5_000,
+        snapshot_enabled: false,
+        snapshot_on_hygiene: false,
+        auto_hydrate: true,
     }
 }