fix(P0): 生产矩阵审计暴露 2 个崩溃恢复丢数据 bug — ① FileManager 页面 id 崩溃回退（allocatePageIds 后 saveMeta 前中断 → nextPageId 回退 → 恢复期页面复用被 compaction 误删，kv 2万行+加密崩溃丢75%）：init 以现存最大页面 id+1 为准；② LSM.flush 剩余数据与 compaction 并发写 meta（产物 saveMeta 被覆盖成孤儿 → 优雅关闭重开丢75%）：剩余落盘挂链串行。新增 13 组合矩阵审计（后端×特性×功能全量验收）

tests/zz-dbg.test.ts

@@ -0,0 +1,24 @@
+import { AriaEngine } from '../src/engine/aria/index';
+import { createSchema } from '../src/table/schema';
+
+it('dbg: call fk directly', async () => {
+  const engine = new AriaEngine({ storageBackend: 'memory' } as never);
+  await engine.open('dbg-fk2', 1);
+  await engine.createTable(createSchema('parent', {
+    id: { type: 'string', primaryKey: true },
+  }));
+  await engine.createTable(createSchema('child', {
+    id: { type: 'string', primaryKey: true },
+    pid: { type: 'string', references: 'parent:id', onDelete: 'CASCADE' },
+  }));
+  await engine.insert('parent', [{ id: 'p1' }]);
+  await engine.insert('child', [{ id: 'c1', pid: 'p1' }]);
+  const wal: unknown[] = [];
+  const n = await (engine as any).applyForeignKeyRules('parent', 'p1', wal, new Set<string>());
+  console.log('fk direct result:', n, 'wal records:', wal.length);
+  console.log('child count after fk:', await engine.count('child'));
+  // 手动 CASCADE 验证
+  const c = await (engine as any).lsm.get('child:c1');
+  console.log('child:c1 in lsm:', c ? 'YES' : 'NO');
+  await engine.close();
+});