feat(models+gate): 模型按项目可配置(默认 opus-4.8) + diff 声明外文件硬闸

① 模型可配置（项目维度，默认 opus-4.8）
- 新增 projects.models（JSON，按角色 executor/planner/reviewer/conflict
  覆盖，值可为字符串=全复杂度统一 或 {easy,medium,hard} 分档）
- models.ts 重构 resolveModel：优先级 项目级 models > 旧 project.model
  (仅 executor/planner) > env > 默认 DEFAULT_MODEL(opus-4.8)
- 取消内置 fable/sonnet 分档默认：所有角色默认 opus-4.8（彻底回避 fable-5
  不可用问题，需要时项目级显式配置即可）；回退链改 opus→sonnet→fable
- API PATCH /projects 透传 models；sanitizeModels 落库校验

② diff 声明外文件闸（task.scopeFiles）
- 新增 tasks.scope_files（JSON glob/路径数组）
- checks.ts: globToRegExp/matchesAnyGlob + scopeFileGate（改动文件越界=硬闸，
  空声明跳过，git 出错不拦截）；pipeline runApproveGates 接入
- planner 拆解新增每子任务 files 字段：prompt 要求 + parseDecompose 解析 +
  ingest 落 scopeFiles，自动填充声明范围
- executor prompt 注入「声明文件范围约束」，让 agent 知边界（gate 才公平）

迁移：projects.models / tasks.scope_files 走 ensureColumn 幂等迁移（旧库补列）
测试：models 默认/配置/优先级、scope glob/gate、planner files 解析、
      store 持久化往返、迁移补列 —— 237 通过

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

test/store.test.ts

@@ -20,6 +20,47 @@ test('project + task creation, complexity routes initial status', () => {
   s.close();
 });
 
+test('patchProject models：持久化 + 读回（字符串/对象形式，非法值丢弃，null 清空）', () => {
+  const s = freshStore();
+  const p = s.createProject({ name: 'mdl', repoPath: '/tmp/mdl-' + Math.random() });
+  assert.equal(p.models, null);
+
+  const up = s.patchProject(p.id, {
+    models: {
+      executor: { easy: 'claude-sonnet-4-6', hard: 'claude-opus-4-8' },
+      reviewer: 'claude-fable-5',
+      // @ts-expect-error 测试非法角色被丢弃
+      bogus: 'x',
+    },
+  });
+  assert.deepEqual(up.models, {
+    executor: { easy: 'claude-sonnet-4-6', hard: 'claude-opus-4-8' },
+    reviewer: 'claude-fable-5',
+  });
+  // 读回（走 mapper）一致
+  assert.deepEqual(s.getProject(p.id)!.models, up.models);
+
+  // null 清空
+  const cleared = s.patchProject(p.id, { models: null });
+  assert.equal(cleared.models, null);
+  s.close();
+});
+
+test('task scopeFiles：create + patch 持久化与读回，去空白/空数组→null', () => {
+  const s = freshStore();
+  const p = s.createProject({ name: 'scp', repoPath: '/tmp/scp-' + Math.random() });
+  const t = s.createTask({ projectId: p.id, title: 'x', complexity: 'easy', scopeFiles: [' src/** ', '', 'lib/a.ts'] });
+  assert.deepEqual(t.scopeFiles, ['src/**', 'lib/a.ts']);   // 去空白 + 丢空项
+  assert.deepEqual(s.getTask(t.id)!.scopeFiles, ['src/**', 'lib/a.ts']);
+
+  const patched = s.patchTask(t.id, { scopeFiles: ['only.ts'] });
+  assert.deepEqual(patched.scopeFiles, ['only.ts']);
+
+  const emptied = s.patchTask(t.id, { scopeFiles: [] });
+  assert.equal(emptied.scopeFiles, null);                    // 空数组 → null（不限范围）
+  s.close();
+});
+
 test('Easy 路径：写操作 → ready → nextExecutable 领取', () => {
   const s = freshStore();
   const p = s.createProject({ name: 'e', repoPath: '/tmp/e-' + Math.random() });