diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8f4f211..8e37b50 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,19 @@ All notable changes to MetonaSqlark will be documented in this file.
 
 ### Fixed
 
+- **页面 id 崩溃回退导致静默丢数据（P0）** — FileManager `allocatePageIds` 在分配页面后、
+  `saveMeta` 持久化 nextPageId 前崩溃 → `__aria_meta` 停留在旧水位 → 恢复时页面 id 复用
+  （覆盖崩溃前旧页面）→ 恢复期 compaction 按 meta.pageIds 删除"旧"SSTable 时误删被复用的
+  新数据页面 → 崩溃恢复后静默丢 75%（kv 后端 2 万行 + 加密 + 双索引场景复现 5228/20000）。
+  修复：`init` 以"现存最大页面 id + 1"为准（单调不回退，绝不复用已存在页面）
+- **LSM.flush 剩余数据与 compaction 并发写 meta（P0）** — `flush()` 对 immutable/memtable
+  的剩余落盘直接 await（不在链上），与链上 compaction 并发写 SSTable meta：compaction 产物
+  `saveMeta` 后，memtable flush 的 `saveMeta` 读到中间态列表（含 compaction 产物）→ 覆盖产物
+  引用 → compaction 产物变孤儿 → 主表/索引数据静默丢失（kv 后端优雅关闭后重开丢 75%）。
+  修复：剩余落盘挂链串行（memtable flush 在 compaction 之后），meta 无竞态
+- **生产矩阵审计**（13 个组合全量验收）：后端（opfs/kv/memory）× 特性（页面化/加密/压缩/
+  WAL 开关/同步模式）× 功能（CRUD/双索引/事务/主键变更/级联删除/崩溃恢复）——
+  新增 `tests/engine/aria-matrix-audit.test.ts`，暴露并修复上述 2 个 P0
 - **二级索引范围扫描漏读尾部数据（P0）** — SSTable 索引块记录的是"块内最后一个 key"
   （builder 约定），读端 `locateBlockLE` 却按块首 key 语义二分：范围查询 endKey 落在
   某块尾部时，下一块（尾 key 越界但首 key 仍在范围内）被排除 → 二级索引条件查询
diff --git a/src/engine/aria/index/lsm.ts b/src/engine/aria/index/lsm.ts
index 9b10df2..5cb50db 100644
--- a/src/engine/aria/index/lsm.ts
+++ b/src/engine/aria/index/lsm.ts
@@ -573,15 +573,21 @@ export class LSM {
     }
     // v0.4.3-fix: 循环等待级联任务（flush 完成可能触发新的 compaction）
     await this.drainChain();
-    // 若仍有 frozen 数据未刷盘，在链尾追加
+    // v0.6.1-fix(P0): 剩余数据 flush 必须挂链串行 —— 此前直接 await 执行，
+    // 与链上 compaction 并发写 SSTable meta：compaction 产物 saveMeta 后，
+    // memtable flush 的 saveMeta 读到中间态列表（含 compaction 产物）→ 覆盖产物
+    // 引用 → compaction 产物变孤儿 → 索引/主表数据静默丢失（优雅关闭后重开丢 75%）。
+    // 挂链后按序执行（memtable flush 在 compaction 之后），meta 无竞态。
     if (this.immutableMemtable) {
       const frozen = this.immutableMemtable;
-      await this.flushImmutableAsync(frozen);
+      this.flushChain = this.enqueueOnChain(() => this.flushImmutableAsync(frozen));
     }
     if (this.memtable.getEntryCount() > 0) {
       this.freezeMemtable();
       const frozen = this.immutableMemtable;
-      if (frozen) await this.flushImmutableAsync(frozen);
+      if (frozen) {
+        this.flushChain = this.enqueueOnChain(() => this.flushImmutableAsync(frozen));
+      }
     }
     this.frozenMemtables = [];
     // 刷盘完成后级联调度可能触发 compaction → 排空到稳定
diff --git a/src/engine/aria/store/file_manager.ts b/src/engine/aria/store/file_manager.ts
index 3d91c87..d9cedcd 100644
--- a/src/engine/aria/store/file_manager.ts
+++ b/src/engine/aria/store/file_manager.ts
@@ -28,11 +28,24 @@ export class FileManager implements PageIO {
   async init(dbName: string): Promise<void> {
     this.dbName = dbName;
     const meta = await this.backend.read('__aria_meta');
+    let nextPageId = 1;
     if (meta && meta instanceof ArrayBuffer && meta.byteLength >= 4) {
-      const view = new DataView(meta);
-      this.nextPageId = view.getUint32(0, false);
-    } else {
-      this.nextPageId = 1;
+      nextPageId = new DataView(meta).getUint32(0, false);
+    }
+    // v0.6.1-fix(P0): 崩溃一致性 —— allocatePageIds 的 saveMeta 可能在分配
+    // 页面后被崩溃中断（nextPageId 回退）。恢复时若按回退值继续分配，
+    // 页面 id 复用会覆盖旧页面；随后 compaction 按 meta.pageIds 删除"旧"SSTable
+    // 时误删被复用的新数据 → 崩溃恢复后静默丢数据（kv 后端 2 万行丢 75%）。
+    // 修复：以"现存最大页面 id + 1"为准（单调不回退，绝不复用已存在页面）。
+    const keys = await this.backend.listKeys();
+    for (const k of keys) {
+      if (k.startsWith('pg_')) {
+        const id = Number.parseInt(k.slice(3), 10);
+        if (!Number.isNaN(id) && id + 1 > nextPageId) nextPageId = id + 1;
+      }
+    }
+    this.nextPageId = nextPageId;
+    if (!meta || !(meta instanceof ArrayBuffer) || meta.byteLength < 4 || nextPageId !== new DataView(meta as ArrayBuffer).getUint32(0, false)) {
       await this.saveMeta();
     }
     this.metaLoaded = true;
diff --git a/tests/engine/aria-matrix-audit.test.ts b/tests/engine/aria-matrix-audit.test.ts
new file mode 100644
index 0000000..5bc82a7
--- /dev/null
+++ b/tests/engine/aria-matrix-audit.test.ts
@@ -0,0 +1,317 @@
+/**
+ * v0.6.1 生产矩阵审计 — 模式 × 功能全组合验收
+ *
+ * 后端（opfs/kv/memory）× 特性（页面化/加密/压缩/WAL开关/同步模式）×
+ * 功能（CRUD/二级索引/事务/崩溃恢复/主键变更一致性）
+ *
+ * 目标：全部组合生产级可用。任一组合同等断言 —— 数据完整、索引一致、崩溃恢复不丢。
+ */
+import { AriaEngine } from '../../src/engine/aria/index';
+import { createSchema } from '../../src/table/schema';
+import { SharedMemoryBackend } from '../../src/engine/kvstore/shared_memory_medium';
+import { installOPFSMock } from '../helpers/opfs-mock';
+
+let counter = 0;
+function uniqueDB(): string {
+  return `mx-${Date.now()}-${++counter}-${Math.random().toString(36).slice(2, 6)}`;
+}
+
+const SCHEMA = () => createSchema('big', {
+  id: { type: 'string', primaryKey: true },
+  val: { type: 'number' },
+  tag: { type: 'string', index: true },
+  grp: { type: 'number', index: true },
+  name: { type: 'string' },
+});
+
+/** 写入 total 行（tag/grp 双索引） */
+async function seed(engine: AriaEngine, table: string, total: number): Promise<void> {
+  for (let batch = 0; batch < total / 1000; batch++) {
+    const rows = [] as Record<string, unknown>[];
+    for (let i = 0; i < 1000; i++) {
+      const idx = batch * 1000 + i;
+      rows.push({ id: `k${idx}`, val: idx, tag: `t${idx % 10}`, grp: idx % 5, name: `U${idx}` });
+    }
+    await engine.insert(table, rows);
+  }
+}
+
+/** 双索引完整性断言 */
+async function assertIndexes(engine: AriaEngine, table: string, total: number): Promise<void> {
+  expect(await engine.count(table)).toBe(total);
+  for (let t = 0; t < 10; t++) {
+    expect(await engine.find(table, { table, where: { tag: `t${t}` } })).toHaveLength(total / 10);
+  }
+  for (let g = 0; g < 5; g++) {
+    expect(await engine.find(table, { table, where: { grp: g } })).toHaveLength(total / 5);
+  }
+}
+
+/** 崩溃恢复：关闭后端 → 新引擎重开同库 */
+async function reopen(dbName: string, config: Record<string, unknown>): Promise<AriaEngine> {
+  const engine2 = new AriaEngine(config as never);
+  await engine2.open(dbName, 1);
+  return engine2;
+}
+
+beforeEach(() => {
+  SharedMemoryBackend.clearRegistry();
+  installOPFSMock(new Map());
+});
+
+describe('生产矩阵审计 — 后端 × 核心功能', () => {
+  const coreConfig = (backend: string): Record<string, unknown> => ({
+    storageBackend: backend,
+    memtableSizeThreshold: 256 * 1024,
+    checkpointInterval: 5000,
+    walSyncMode: 'full',
+  });
+
+  it('kv × 3 万行 + 双索引 + 事务 + 崩溃恢复', async () => {
+    const dbName = uniqueDB();
+    const engine = new AriaEngine(coreConfig('kv') as never);
+    await engine.open(dbName, 1);
+    await engine.createTable(SCHEMA());
+    await seed(engine, 'big', 30000);
+    // 事务：提交一批更新
+    await engine.beginTransaction();
+    for (let i = 0; i < 100; i++) {
+      await engine.update('big', { table: 'big', where: { id: `k${i}` } }, { name: `Tx${i}` });
+    }
+    await engine.commitTransaction();
+    await assertIndexes(engine, 'big', 30000);
+    const row = await engine.find('big', { table: 'big', where: { id: 'k50' } });
+    expect(row[0].name).toBe('Tx50');
+    // 事务回滚不产生残留
+    await engine.beginTransaction();
+    for (let i = 1000; i < 1100; i++) {
+      await engine.update('big', { table: 'big', where: { id: `k${i}` } }, { name: `Rx${i}` });
+    }
+    await engine.rollbackTransaction();
+    expect((await engine.find('big', { table: 'big', where: { id: 'k1050' } }))[0].name).toBe('U1050');
+    // 崩溃恢复
+    await (engine as any).backend.close();
+    (engine as any).opened = false;
+    const engine2 = await reopen(dbName, coreConfig('kv'));
+    await assertIndexes(engine2, 'big', 30000);
+    expect((await engine2.find('big', { table: 'big', where: { id: 'k50' } }))[0].name).toBe('Tx50');
+    await engine2.close();
+  }, 180000);
+
+  it('opfs × 3 万行 + 双索引 + 崩溃恢复', async () => {
+    const dbName = uniqueDB();
+    const engine = new AriaEngine(coreConfig('opfs') as never);
+    await engine.open(dbName, 1);
+    await engine.createTable(SCHEMA());
+    await seed(engine, 'big', 30000);
+    await assertIndexes(engine, 'big', 30000);
+    await (engine as any).backend.close();
+    (engine as any).opened = false;
+    const engine2 = await reopen(dbName, coreConfig('opfs'));
+    await assertIndexes(engine2, 'big', 30000);
+    await engine2.close();
+  }, 180000);
+
+  it('memory × 2 万行 + 双索引 + 事务回滚', async () => {
+    const engine = new AriaEngine(coreConfig('memory') as never);
+    await engine.open(uniqueDB(), 1);
+    await engine.createTable(SCHEMA());
+    await seed(engine, 'big', 20000);
+    await engine.beginTransaction();
+    await engine.update('big', { table: 'big', where: { id: 'k7' } }, { tag: 't9' });
+    await engine.rollbackTransaction();
+    await assertIndexes(engine, 'big', 20000);
+    // 更新后索引一致（无脏数据）——k7 从 t7 移到 t9
+    await engine.update('big', { table: 'big', where: { id: 'k7' } }, { tag: 't9' });
+    expect(await engine.find('big', { table: 'big', where: { tag: 't9' } })).toHaveLength(2001);
+    expect(await engine.find('big', { table: 'big', where: { tag: 't7' } })).toHaveLength(1999);
+    await engine.close();
+  }, 120000);
+});
+
+describe('生产矩阵审计 — 特性组合', () => {
+  it('kv × 加密 × 压缩 × 页面化（默认开）→ 2 万行 + 崩溃恢复', async () => {
+    const dbName = uniqueDB();
+    const cfg = {
+      storageBackend: 'kv', memtableSizeThreshold: 256 * 1024, checkpointInterval: 5000,
+      walSyncMode: 'full', compression: true, encryption: { password: 'matrix-secret' },
+    };
+    const engine = new AriaEngine(cfg as never);
+    await engine.open(dbName, 1);
+    await engine.createTable(SCHEMA());
+    await seed(engine, 'big', 20000);
+    await assertIndexes(engine, 'big', 20000);
+    await (engine as any).backend.close();
+    (engine as any).opened = false;
+    const engine2 = await reopen(dbName, cfg);
+    await assertIndexes(engine2, 'big', 20000);
+    await engine2.close();
+    // 错误密码必须拒绝打开
+    const bad = new AriaEngine({ ...cfg, encryption: { password: 'wrong' } } as never);
+    await expect(bad.open(dbName, 1)).rejects.toThrow();
+  }, 180000);
+
+  it('kv × pageStorage:false（整 value）→ 2 万行 + 崩溃恢复', async () => {
+    const dbName = uniqueDB();
+    const cfg = {
+      storageBackend: 'kv', memtableSizeThreshold: 256 * 1024, checkpointInterval: 5000,
+      walSyncMode: 'full', pageStorage: false,
+    };
+    const engine = new AriaEngine(cfg as never);
+    await engine.open(dbName, 1);
+    await engine.createTable(SCHEMA());
+    await seed(engine, 'big', 20000);
+    await assertIndexes(engine, 'big', 20000);
+    await (engine as any).backend.close();
+    (engine as any).opened = false;
+    const engine2 = await reopen(dbName, cfg);
+    await assertIndexes(engine2, 'big', 20000);
+    await engine2.close();
+  }, 180000);
+
+  it('opfs × 加密 × 压缩 × 页面化全开 → 2 万行 + 崩溃恢复', async () => {
+    const dbName = uniqueDB();
+    const cfg = {
+      storageBackend: 'opfs', memtableSizeThreshold: 256 * 1024, checkpointInterval: 5000,
+      walSyncMode: 'full', compression: true, encryption: { password: 'matrix-secret' },
+      pageStorage: true,
+    };
+    const engine = new AriaEngine(cfg as never);
+    await engine.open(dbName, 1);
+    await engine.createTable(SCHEMA());
+    await seed(engine, 'big', 20000);
+    await assertIndexes(engine, 'big', 20000);
+    await (engine as any).backend.close();
+    (engine as any).opened = false;
+    const engine2 = await reopen(dbName, cfg);
+    await assertIndexes(engine2, 'big', 20000);
+    await engine2.close();
+  }, 180000);
+
+  it('opfs × walEnabled:false → 写入 + 优雅关闭后重开完整', async () => {
+    const dbName = uniqueDB();
+    const cfg = {
+      storageBackend: 'opfs', memtableSizeThreshold: 128 * 1024, checkpointInterval: 2000,
+      walEnabled: false, pageStorage: false,
+    };
+    const engine = new AriaEngine(cfg as never);
+    await engine.open(dbName, 1);
+    await engine.createTable(SCHEMA());
+    await seed(engine, 'big', 20000);
+    await assertIndexes(engine, 'big', 20000);
+    // 优雅关闭：close 等待后台链 + checkpoint 落盘 → 重开完整
+    await engine.close();
+    const engine2 = await reopen(dbName, cfg);
+    await assertIndexes(engine2, 'big', 20000);
+    await engine2.close();
+  }, 180000);
+
+  it('kv × walEnabled:false → 写入 + 优雅关闭后重开完整', async () => {
+    const dbName = uniqueDB();
+    const cfg = {
+      storageBackend: 'kv', memtableSizeThreshold: 128 * 1024, checkpointInterval: 2000,
+      walEnabled: false, pageStorage: false,
+    };
+    const engine = new AriaEngine(cfg as never);
+    await engine.open(dbName, 1);
+    await engine.createTable(SCHEMA());
+    await seed(engine, 'big', 20000);
+    await assertIndexes(engine, 'big', 20000);
+    await engine.close();
+    const engine2 = await reopen(dbName, cfg);
+    await assertIndexes(engine2, 'big', 20000);
+    await engine2.close();
+  }, 180000);
+
+  it('kv × walSyncMode:batch → 优雅关闭后重开完整（崩溃保底已 checkpoint 数据）', async () => {
+    const dbName = uniqueDB();
+    const cfg = {
+      storageBackend: 'kv', memtableSizeThreshold: 256 * 1024, checkpointInterval: 3000,
+      walSyncMode: 'batch',
+    };
+    const engine = new AriaEngine(cfg as never);
+    await engine.open(dbName, 1);
+    await engine.createTable(SCHEMA());
+    await seed(engine, 'big', 20000);
+    await assertIndexes(engine, 'big', 20000);
+    await engine.close();
+    const engine2 = await reopen(dbName, cfg);
+    await assertIndexes(engine2, 'big', 20000);
+    await engine2.close();
+  }, 180000);
+
+  it('opfs × walSyncMode:none → 优雅关闭后重开完整（checkpoint 兜底）', async () => {
+    const dbName = uniqueDB();
+    const cfg = {
+      storageBackend: 'opfs', memtableSizeThreshold: 128 * 1024, checkpointInterval: 3000,
+      walSyncMode: 'none', pageStorage: false,
+    };
+    const engine = new AriaEngine(cfg as never);
+    await engine.open(dbName, 1);
+    await engine.createTable(SCHEMA());
+    await seed(engine, 'big', 20000);
+    await assertIndexes(engine, 'big', 20000);
+    await engine.close();
+    const engine2 = await reopen(dbName, cfg);
+    await assertIndexes(engine2, 'big', 20000);
+    await engine2.close();
+  }, 180000);
+});
+
+describe('生产矩阵审计 — 主键变更索引一致性（三后端）', () => {
+  it('kv × 主键变更：新旧索引无脏数据', async () => {
+    const engine = new AriaEngine({ storageBackend: 'kv', memtableSizeThreshold: 256 * 1024, checkpointInterval: 100000 } as never);
+    await engine.open(uniqueDB(), 1);
+    await engine.createTable(SCHEMA());
+    await engine.insert('big', [{ id: 'a1', val: 1, tag: 'x', grp: 1, name: 'A' }]);
+    // 主键 a1 → b1（tag/grp 不变）
+    await engine.update('big', { table: 'big', where: { id: 'a1' } }, { id: 'b1' });
+    expect(await engine.count('big')).toBe(1);
+    expect(await engine.find('big', { table: 'big', where: { tag: 'x' } })).toHaveLength(1);
+    expect(await engine.find('big', { table: 'big', where: { id: 'a1' } })).toHaveLength(0);
+    await engine.close();
+  }, 60000);
+
+  it('opfs × 主键变更 + 崩溃恢复：索引一致', async () => {
+    const dbName = uniqueDB();
+    const engine = new AriaEngine({ storageBackend: 'opfs', memtableSizeThreshold: 256 * 1024, checkpointInterval: 100000, pageStorage: false } as never);
+    await engine.open(dbName, 1);
+    await engine.createTable(SCHEMA());
+    for (let i = 0; i < 5000; i++) {
+      await engine.insert('big', [{ id: `k${i}`, val: i, tag: `t${i % 10}`, grp: i % 5, name: `U${i}` }]);
+    }
+    for (let i = 0; i < 5000; i += 10) {
+      await engine.update('big', { table: 'big', where: { id: `k${i}` } }, { id: `p${i}` });
+    }
+    await (engine as any).backend.close();
+    (engine as any).opened = false;
+    const engine2 = new AriaEngine({ storageBackend: 'opfs', memtableSizeThreshold: 256 * 1024, checkpointInterval: 100000, pageStorage: false } as never);
+    await engine2.open(dbName, 1);
+    expect(await engine2.count('big')).toBe(5000);
+    for (let t = 0; t < 10; t++) {
+      expect(await engine2.find('big', { table: 'big', where: { tag: `t${t}` } })).toHaveLength(500);
+    }
+    await engine2.close();
+  }, 120000);
+
+  it('memory × 级联删除 + 索引清理', async () => {
+    const engine = new AriaEngine({ storageBackend: 'memory', memtableSizeThreshold: 256 * 1024 } as never);
+    await engine.open(uniqueDB(), 1);
+    await engine.createTable(createSchema('parent', {
+      id: { type: 'string', primaryKey: true },
+      tag: { type: 'string', index: true },
+    }));
+    await engine.createTable(createSchema('child', {
+      id: { type: 'string', primaryKey: true },
+      pid: { type: 'string', references: 'parent.id', onDelete: 'CASCADE', index: true },
+    }));
+    for (let i = 0; i < 2000; i++) {
+      await engine.insert('parent', [{ id: `p${i}`, tag: `t${i % 10}` }]);
+      await engine.insert('child', [{ id: `c${i}`, pid: `p${i}` }]);
+    }
+    await engine.delete('parent', { table: 'parent', where: { id: 'p5' } });
+    expect(await engine.count('child')).toBe(1999);
+    expect(await engine.find('child', { table: 'child', where: { pid: 'p5' } })).toHaveLength(0);
+    await engine.close();
+  }, 60000);
+});
diff --git a/tests/zz-dbg.test.ts b/tests/zz-dbg.test.ts
new file mode 100644
index 0000000..e72f9c1
--- /dev/null
+++ b/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();
+});