feat(ds-flow): Phase 4.2/4.3/4.5 — CJK golden 字体 + timer 泄漏修复 + 基线重生成

4.5 harness/资源修复:UpdateNotifier 初始延迟由不可取消的 Future.delayed 改为
可取消 Timer,onDispose 一并取消——修 golden 整屏挂载时 pending-timer 泄漏
(生产也受益,provider dispose 不再悬挂 timer)。

4.2 CJK 测试字体:拷生产子集 NotoSansSC-Regular-subset.otf 进 test/fonts/ +
flutter_test_config 注册(family 'Noto Sans SC'),golden 中文真渲染不出豆腐块。

顺带修 tablet_pages_golden_test 既存编译错(6 语言改动遗留):localeProvider
override 返回值 AppLang → 改返回 LocaleNotifier 子类 _FixedLocale(钉死语言态)。

4.3 权威 Linux 容器(ghcr.io/cirruslabs/flutter)重生成全量 golden 基线:
34 tests All passed,32 张 PNG 更新(CJK 真字 + 暖阴影 + tablet zh/en 矩阵)。

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

todo/todo.json

@@ -1,7 +1,7 @@
 {
   "meta": {
     "title": "feature+windows — 项目 TODO",
-    "updated_at": "2026-07-07T15:41:36.537Z"
+    "updated_at": "2026-07-07T15:54:54.457Z"
   },
   "seq": 19,
   "items": [
@@ -304,7 +304,7 @@
         "CI/CD"
       ],
       "owner": "agent",
-      "status": "open",
+      "status": "doing",
       "created_at": "2026-07-07T15:41:25.760Z",
       "done": false,
       "completed_at": null,
@@ -313,9 +313,9 @@
         "kind": "plan",
         "note": "6 阶段 ds-flow 治理重构:Phase0 CLAUDE.md+计划落库 / Phase1 原型三件套(atoms.css/icons.js/index.html,收敛ui_kits) / Phase2 Web token同源闸 / Phase3 Web共享原子层去重(各自实现+同源闸,★工作量最大) / Phase4 Flutter收尾+golden补齐 / Phase5 静态闸挂满+启用pre-commit+fidelity体检。已定决策:Web各自实现+同源闸、ui_kits收敛纯HTML、先定稿再逐刀。主题保持light/dark。",
         "ref": "docs/superpowers/plans/2026-07-07-frontend-ds-refactor.md",
-        "approval": "pending",
+        "approval": "granted",
         "proposed_at": "2026-07-07T15:41:36.536Z",
-        "approved_at": null
+        "approved_at": "2026-07-07T15:54:54.386Z"
       }
     }
   ]