refactor(engine): make StrictEngine, ColumnarEngine, and HtapBridge interior-mutable

Replaces outer `Mutex<Engine>` wrappers with per-engine interior locking:
- `StrictEngine` is natively `Send + Sync`; all public methods take `&self`
- `ColumnarEngine` moves to `RwLock<CollectionMap>` with per-collection
  `Mutex<CollectionState>` so concurrent reads on different collections
  do not block each other
- `HtapBridge` wraps its view map in a `Mutex` and exposes `&self` methods
- `RedbStorage` wraps `Database` in `Arc<Mutex<_>>` so async methods can
  move a cheap clone into `spawn_blocking` closures

All call sites in `NodeDbLite`, the query DDL layer, the sync transport,
and integration tests are updated to drop the outer `.lock()` calls and
await engine futures directly, eliminating `block_in_place` workarounds
throughout the codebase.

Author: farhan-syah

nodedb-lite/examples/live_sync.rs

@@ -147,6 +147,7 @@ async fn test_delta_push() -> Result<(), String> {
         peer_id: 42,
         mutation_id: 1,
         checksum: 0,
+        device_valid_time_ms: None,
     };
     ws.send(Message::Binary(
         SyncFrame::encode_or_empty(SyncMessageType::DeltaPush, &delta)
@@ -321,6 +322,7 @@ async fn test_real_loro_delta() -> Result<(), String> {
         peer_id: 100,
         mutation_id: 1,
         checksum: 0,
+        device_valid_time_ms: None,
     };
     ws.send(Message::Binary(
         SyncFrame::encode_or_empty(SyncMessageType::DeltaPush, &delta_msg)
@@ -384,6 +386,7 @@ async fn test_concurrent_deltas() -> Result<(), String> {
             peer_id: 200 + i as u64 + 1,
             mutation_id: i as u64 + 1,
             checksum: 0,
+            device_valid_time_ms: None,
         };
         ws.send(Message::Binary(
             SyncFrame::encode_or_empty(SyncMessageType::DeltaPush, &msg)
@@ -433,6 +436,7 @@ async fn test_rls_violation() -> Result<(), String> {
         peer_id: 500,
         mutation_id: 99,
         checksum: 0,
+        device_valid_time_ms: None,
     };
     ws.send(Message::Binary(
         SyncFrame::encode_or_empty(SyncMessageType::DeltaPush, &msg)
@@ -481,6 +485,7 @@ async fn test_shape_snapshot_lsn() -> Result<(), String> {
             peer_id: 300,
             mutation_id: 1,
             checksum: 0,
+            device_valid_time_ms: None,
         };
         ws.send(Message::Binary(
             SyncFrame::encode_or_empty(SyncMessageType::DeltaPush, &msg)

nodedb-lite/examples/load_test.rs

@@ -172,6 +172,7 @@ async fn run_client(
             peer_id: 1000 + id as u64,
             mutation_id: 1,
             checksum: 0,
+            device_valid_time_ms: None,
         };
         if ws
             .send(Message::Binary(