feat(8.0): zero-config finalize + cut JS quantization (config.vector = recall + persistMode)

tests/unit/performance/add-performance.test.ts

@@ -117,10 +117,13 @@ describe('add() Performance Regression Tests', () => {
       expect(storageType).toBe('memory')
     })
 
-    it('should use immediate persistence for memory storage', async () => {
-      // Memory storage should use immediate mode (already fast)
+    it('should use deferred persistence for memory storage', async () => {
+      // 8.0 adaptive default: memory storage uses 'deferred' — nothing survives
+      // the process anyway, so per-add persistence writes are pure overhead.
+      // (Filesystem storage gets 'immediate'; an explicit config.vector.persistMode
+      // overrides either way.)
       const index = (brain as any).index
-      expect(index.persistMode).toBe('immediate')
+      expect(index.persistMode).toBe('deferred')
     })
   })
 })