fix(memory): defensive markNeedsReindex + drain setImmediate in legacy tests

- store.ts: wrap markMemoryNeedsReindex in safeMarkNeedsReindex helper that swallows
  errors when the DB is no longer available (e.g. test teardown after the parent
  promise resolved). Prevents fire-and-forget vector upserts from triggering
  unhandledRejection in tests.
- memory-store.test.ts: drain setImmediate in afterEach/after hooks so pending
  vector upsert tasks settle before DATA_DIR is removed.
- memory-settings.test.ts: extend deepEqual expected shape with the 7 new fields
  introduced by plan 21 F5 (embeddingSource, embeddingProviderModel,
  transformersEnabled, staticEnabled, rerankEnabled, rerankProviderModel,
  vectorStore).

tests/unit/memory-settings.test.ts

@@ -23,6 +23,14 @@ describe("memory settings helpers", () => {
       retentionDays: 1,
       strategy: DEFAULT_MEMORY_SETTINGS.strategy,
       skillsEnabled: true,
+      // Plan 21 — Memory Engine Redesign extended fields (default values)
+      embeddingSource: DEFAULT_MEMORY_SETTINGS.embeddingSource,
+      embeddingProviderModel: DEFAULT_MEMORY_SETTINGS.embeddingProviderModel,
+      transformersEnabled: DEFAULT_MEMORY_SETTINGS.transformersEnabled,
+      staticEnabled: DEFAULT_MEMORY_SETTINGS.staticEnabled,
+      rerankEnabled: DEFAULT_MEMORY_SETTINGS.rerankEnabled,
+      rerankProviderModel: DEFAULT_MEMORY_SETTINGS.rerankProviderModel,
+      vectorStore: DEFAULT_MEMORY_SETTINGS.vectorStore,
     });
   });
 

tests/unit/memory-store.test.ts

@@ -52,11 +52,29 @@ function insertMemoryRow({
   ).run(id, apiKeyId, sessionId, type, key, content, metadata, createdAt, updatedAt, expiresAt);
 }
 
+/**
+ * Drain pending setImmediate callbacks scheduled by store.createMemory/updateMemory
+ * (which fire-and-forget the vector upsert). Without this, the test runner may end
+ * before the async tasks resolve, causing "asynchronous activity after test ended"
+ * errors when the upsert later tries to touch the DB we already tore down.
+ */
+async function drainSetImmediate(rounds = 3): Promise<void> {
+  for (let i = 0; i < rounds; i++) {
+    await new Promise((resolve) => setImmediate(resolve));
+  }
+}
+
 test.beforeEach(async () => {
   await resetStorage();
 });
 
+test.afterEach(async () => {
+  // Allow vector upsert fire-and-forget to settle before the next test resets DATA_DIR.
+  await drainSetImmediate();
+});
+
 test.after(async () => {
+  await drainSetImmediate();
   core.resetDbInstance();
   fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
 });