feat: 回收站、批量编辑、合并导入与标签治理

- 数据：Task 增加 deletedAt，schema v2→v3；删除改为软删除，保留 30 天后自动清理
- 回收站：支持恢复、永久删除、二次确认清空；导航栏入口带数量角标
- 批量编辑：多选后统一移动列、改优先级、标签增删、设置截止日、归档
- 合并导入：按 id 匹配、updatedAt 新者胜；覆盖/合并二选一，执行前自动快照
- 标签治理：全局重命名、合并、删除；回收站任务不参与改写
- 看板语义读取统一改用 activeTasks，避免已删除任务泄漏到统计、今日与标签下拉
- UI：回收站图标与备份统一尺寸；批量编辑条统一控件高度并分组
- 测试：705 个单测通过，补充迁移、回收站、批量编辑、合并与标签用例

src/data/schema.spec.ts

@@ -26,6 +26,7 @@ function validTask(overrides: Record<string, unknown> = {}): Record<string, unkn
     updatedAt: '2026-10-18T00:00:00.000Z',
     completedAt: null,
     archivedAt: null,
+    deletedAt: null,
     ...overrides,
   }
 }
@@ -106,6 +107,18 @@ describe('coerceTask', () => {
     expect(coerceTask(validTask({ archivedAt: null }))?.archivedAt).toBeNull()
   })
 
+  it('非法 deletedAt 收敛为 null', () => {
+    expect(coerceTask(validTask({ deletedAt: 123 }))?.deletedAt).toBeNull()
+    expect(coerceTask(validTask({ deletedAt: null }))?.deletedAt).toBeNull()
+    expect(coerceTask(validTask({ deletedAt: undefined }))?.deletedAt).toBeNull()
+  })
+
+  it('保留合法的 deletedAt', () => {
+    expect(coerceTask(validTask({ deletedAt: '2026-10-19T00:00:00.000Z' }))?.deletedAt).toBe(
+      '2026-10-19T00:00:00.000Z',
+    )
+  })
+
   it('保留合法的 archivedAt', () => {
     expect(coerceTask(validTask({ archivedAt: '2026-10-01T00:00:00.000Z' }))?.archivedAt).toBe(
       '2026-10-01T00:00:00.000Z',
@@ -226,6 +239,51 @@ describe('版本迁移', () => {
     const state = parsePersistedState(v1)
     expect(state.tasks.map((task) => task.archivedAt)).toEqual([null, null])
   })
+
+  it('v2 数据迁移到 v3 时补上 deletedAt，其余字段不变', () => {
+    const v2 = JSON.stringify({
+      schemaVersion: 2,
+      tasks: [
+        {
+          id: 'legacy',
+          title: '归档任务',
+          status: 'done',
+          priority: 2,
+          sortOrder: 1024,
+          createdAt: '2026-01-01T00:00:00.000Z',
+          updatedAt: '2026-01-02T00:00:00.000Z',
+          completedAt: '2026-01-02T00:00:00.000Z',
+          archivedAt: '2026-01-03T00:00:00.000Z',
+        },
+      ],
+    })
+
+    const state = parsePersistedState(v2)
+
+    expect(state.schemaVersion).toBe(SCHEMA_VERSION)
+    expect(state.tasks[0]?.deletedAt).toBeNull()
+    expect(state.tasks[0]?.archivedAt).toBe('2026-01-03T00:00:00.000Z')
+  })
+
+  it('v0/v1/v2 都能一路迁移到 v3', () => {
+    const builds = [
+      () => ({ tasks: [{ id: 'a', title: 'A', status: 'todo', priority: 2 }] }),
+      () => ({ schemaVersion: 1, tasks: [{ id: 'a', title: 'A', status: 'todo', priority: 2 }] }),
+      () => ({ schemaVersion: 2, tasks: [{ id: 'a', title: 'A', status: 'todo', priority: 2 }] }),
+    ]
+
+    for (const build of builds) {
+      const state = parsePersistedState(JSON.stringify(build()))
+      expect(state.schemaVersion).toBe(3)
+      expect(state.tasks[0]?.deletedAt).toBeNull()
+    }
+  })
+
+  it('删除状态在序列化往返后保留', () => {
+    const tasks = coerceTaskList([validTask({ deletedAt: '2026-10-19T00:00:00.000Z' })])
+    const roundTrip = parsePersistedState(serializeState(tasks))
+    expect(roundTrip.tasks[0]?.deletedAt).toBe('2026-10-19T00:00:00.000Z')
+  })
 })
 
 describe('序列化往返', () => {