# Optimize Batch Creation Performance

The performance regression in `create_documents_batch_small` compared to `create_document_small` is due to direct writes to `storage` during entity creations, property updates, and child additions, completely bypassing the `EmbeddedTransaction`'s `_operations` queue. Every `add_child` directly updates and re-serializes the entire children array of a container synchronously, causing quadratic time complexity for batch inserts in a single container.

## Proposed Changes

### 1. [src/Engine/EmbeddedEngine.vala](file:///home/bbarrow/Projects/Implexus/src/Engine/EmbeddedEngine.vala)
- Add an internal accessor for `current_transaction` so that entities can queue operations:
  ```vala
  internal EmbeddedTransaction? current_transaction { get { return _current_transaction; } }
  ```

### 2. [src/Engine/EmbeddedTransaction.vala](file:///home/bbarrow/Projects/Implexus/src/Engine/EmbeddedTransaction.vala)
- Implement `apply_operation` for `OperationType.SET_PROPERTY` to properly apply property updates, OR refactor property updates to queue a full property save (`OperationType.SAVE_PROPERTIES`).
- Since `Document` modifies `_properties` in-memory and multiple `set_entity_property` calls would each record a property, it is optimal to let `EmbeddedTransaction` merge property updates.
- During `commit()`, merge operations or ensure that `save_properties` is called only once per document.
- Add support for Category, Catalogue, and Index creation records if needed, or expand `OperationType.CREATE_ENTITY` to handle them. (Currently `CREATE_ENTITY` metadata storage might require expressions for categories).

### 3. [src/Entities/Container.vala](file:///home/bbarrow/Projects/Implexus/src/Entities/Container.vala)
- Modify `create_container`, `create_document`, `create_category`, `create_catalogue`, `create_index`, and `delete_child` to check if `_engine` is in a transaction.
- If in a transaction, call `record_create_entity` and `record_add_child` instead of writing to `storage` directly.

### 4. [src/Entities/Document.vala](file:///home/bbarrow/Projects/Implexus/src/Entities/Document.vala)
- Modify `save_properties` to check for an active transaction.
- If active, defer the property save to the transaction rather than saving immediately.

### 5. [src/Entities/AbstractEntity.vala](file:///home/bbarrow/Projects/Implexus/src/Entities/AbstractEntity.vala)
- Modify `delete()` to use `record_delete_entity` and `record_remove_child` when inside a transaction.

## Verification Plan
1. Run `implexus-perf` benchmark specifically for `Document` to verify that `create_documents_batch_small` decreases from ~58ms down to effectively ~1-2ms per batch (since the DB write is deferred and batched).
2. The benchmark will validate both performance improvements and correctness (reads/writes in the benchmark must still function correctly).