feat(engine): a protected factory for the generation store — a subclass may substitute one that keeps the contract

src/brainy.ts

@@ -1040,6 +1040,17 @@ export class Brainy<T = any> implements BrainyInterface<T> {
     }
   }
 
+  /**
+   * Factory hook for the generation store, so an engine built on top of this
+   * reference implementation can substitute a `GenerationStore` that keeps
+   * the same behavioural contract (for example, one backed by a native
+   * implementation) — overriding it never changes this engine's own
+   * behaviour, since the default implementation is unchanged.
+   */
+  protected createGenerationStore(storage: BaseStorage): GenerationStore {
+    return new GenerationStore(storage)
+  }
+
   /**
    * Initialize Brainy.
    *
@@ -1297,7 +1308,7 @@ export class Brainy<T = any> implements BrainyInterface<T> {
       // guarantees indexes never observe rolled-back state. Reader-mode
       // instances skip recovery (readers never write; the next writer
       // repairs).
-      this.generationStore = new GenerationStore(this.storage)
+      this.generationStore = this.createGenerationStore(this.storage)
       const generationOpenResult = await step(
         'generation-store.open',
         'reading the generation manifest and committed ranges, opening the fact log and the ' +