实现应用更新清单与关于页

[utopiafar]

关联 issue

Closes #296

变更

• 新增 AppInfo、UpdateManifest、AppUpdateRouter 等服务，支持读取构建信息、解析更新清单、校验安装包大小/hash，并处理有界超时。
• 新增 About Memex 页面与设置入口，展示版本、build、flavor、channel、installer/package，并提供诊断信息复制。
• 接入 Android 原生 app info channel、启动后台检查和本地化文案。

测试

• flutter test --no-pub test/data/services/update_manifest_service_test.dart test/data/services/app_update_service_test.dart test/data/services/app_update_router_test.dart test/ui/settings/widgets/about_memex_page_test.dart
• flutter build apk --debug --flavor globalDev --no-pub
• git diff --check
• Android emulator Medium_Phone_API_35：进入 Personal Center → Settings → About Memex，确认版本/build/flavor/channel/installer/package 可见；Copy Diagnostics 只包含 app/package/version/platform/flavor/region/channel/installer/updateChannel；Check now 在无 manifest/404 场景会结束为可见错误，不会无限 spinner。

[github-actions]

PR AI Review / PR AI 语义预检

中文

• 风险等级：中风险
• 需要人工审核：是
• 黄金链路影响：可能
• 置信度：high
• Workflow run：27593290914

新增统一应用更新系统和关于页面。引入 UpdateManifestService（支持 SHA256 完整性校验和多端点降级）、AppUpdateRouter（多 provider 路由：GitHub APK、Google Play、App Store、Android 商店重定向）和 AppInfoService（构建信息和安装来源查询）。新增 About Memex 设置页面展示版本/渠道/安装来源/更新诊断。替换原有 Early-only 更新卡片，扩展为全渠道统一更新。测试覆盖充分，包含 7 个新测试文件。

影响范围

• service
• ui
• view_model
• i18n
• platform_android
• tests

黄金链路

• platform_entry
• 说明：PR 修改了应用更新检查和安装流程，影响 Android 平台入口行为。更新机制涉及远程 manifest 拉取、APK 下载和 SHA256 校验，属于安全敏感路径。

风险项

• info AppUpdateRouter 包含较多业务逻辑。证据：lib/data/services/app_update_router.dart (561 lines)。
  建议：AppUpdateRouter 作为 service 层协调多个 update provider，当前结构清晰（provider 模式 + 策略选择），但如果后续扩展建议拆分 provider 注册和结果构建逻辑。
• info 更新清单拉取和 APK 校验安全措施到位。证据：lib/data/services/update_manifest_service.dart: verifyManifestSha256=true by default, sha256 sidecar file verification, lib/data/services/app_update_service.dart: _fileSha256(), _normalizeSha256(), SHA256 validation on download and cache reuse, lib/domain/models/update_manifest.dart: _validateProviderFields() enforces sha256 format for github_apk provider。
  建议：安全措施设计良好。建议确认 manifest URL 不会通过日志或诊断信息泄露给用户。
• info 更新检查从 Early-only 扩展为全渠道。证据：lib/main.dart: _scheduleAppUpdateCheck() replaces _scheduleEarlyUpdateCheck(), removed AppUpdateService.isSupported guard, lib/ui/settings/widgets/settings_page.dart: AboutMemexPage replaces EarlyUpdateSettingsCard, removed Platform.isAndroid && AppFlavor.isEarly guard。
  建议：确认 stable 渠道用户看到更新提示是预期行为。当前实现中 Dev 渠道在非手动检查时会跳过（buildInfo.isDev），这是合理的。

测试缺口

• 未发现新的测试缺口。

English

• Risk level: MEDIUM
• Human review required: YES
• Golden path impact: POSSIBLE
• Confidence: high
• Workflow run: 27593290914

Adds a unified app update system and About page. Introduces UpdateManifestService (SHA256 integrity verification with multi-endpoint fallback), AppUpdateRouter (multi-provider routing: GitHub APK, Google Play, App Store, Android store redirect), and AppInfoService (build info and installer source). Adds About Memex settings page showing version/channel/installer/update diagnostics. Replaces the old Early-only update card with a unified cross-channel update system. Test coverage is thorough with 7 new test files.

Affected Areas

• service
• ui
• view_model
• i18n
• platform_android
• tests

Golden Path

• platform_entry
• Rationale: The PR modifies app update checking and installation flow, affecting Android platform entry behavior. The update mechanism involves remote manifest fetching, APK download, and SHA256 verification, which is a security-sensitive path.

Findings

• info AppUpdateRouter contains substantial business logic. Evidence: lib/data/services/app_update_router.dart (561 lines).
  Recommendation: AppUpdateRouter coordinates multiple update providers as a service layer. The current structure is clear (provider pattern + strategy selection), but consider splitting provider registration and result-building logic if it grows further.
• info Update manifest fetching and APK verification security measures are sound. Evidence: lib/data/services/update_manifest_service.dart: verifyManifestSha256=true by default, sha256 sidecar file verification, lib/data/services/app_update_service.dart: _fileSha256(), _normalizeSha256(), SHA256 validation on download and cache reuse, lib/domain/models/update_manifest.dart: _validateProviderFields() enforces sha256 format for github_apk provider.
  Recommendation: Security measures are well-designed. Recommend confirming manifest URLs are not leaked to users via logs or diagnostics output.
• info Update check expanded from Early-only to all channels. Evidence: lib/main.dart: _scheduleAppUpdateCheck() replaces _scheduleEarlyUpdateCheck(), removed AppUpdateService.isSupported guard, lib/ui/settings/widgets/settings_page.dart: AboutMemexPage replaces EarlyUpdateSettingsCard, removed Platform.isAndroid && AppFlavor.isEarly guard.
  Recommendation: Confirm that showing update prompts to stable channel users is intentional. The current implementation skips auto-check for Dev builds (buildInfo.isDev), which is reasonable.

Test Gaps

• No new test gap was reported.

AI review is advisory. Maintainers should verify the result before merging.

[github-actions]

PR Preflight Summary / PR 预检汇总

中文

• 统一结论：低风险：两个预检均已完成，质量预检通过，可走普通手动合并流程。
• Policy preflight：低风险。未命中打回或高风险规则。
• Flutter quality：通过。Analyzer 和 test baseline 均未发现新增问题。
• PR head：1a278323a7deb4ae10792bcf5554e76c65849559
• Policy run：27593290903
• Flutter run：27593292482

English

• Combined result: Low risk: both preflights completed and quality passed; use the normal manual merge flow.
• Policy preflight: LOW RISK. No blocking or high-risk policy signal was found.
• Flutter quality: PASS. Analyzer and test baselines found no newly introduced issue.
• PR head: 1a278323a7deb4ae10792bcf5554e76c65849559
• Policy run: 27593290903
• Flutter run: 27593292482

PR Policy Preflight / PR 规则预检

PR Policy Preflight / PR 规则预检

中文

• 判定：低风险
• 变更文件数：26
• 变更行数：3824
• Diff 是否截断：false

未发现确定性规则问题。

English

• Decision: LOW RISK
• Changed files: 26
• Changed lines: 3824
• Diff truncated: false

No deterministic policy findings.

PR Flutter Quality / Flutter 质量预检

PR Flutter Quality / Flutter 质量预检

中文

• 总体：通过
• Analyzer baseline：通过
• Test baseline：通过

English

• Overall: PASS
• Analyzer baseline: PASS
• Test baseline: PASS

Flutter Analyzer Baseline

• Base issues: 284
• PR issues: 284
• New issues: 0

No new analyzer issues introduced by this PR.

Flutter Test Baseline

• Base failures: 0
• PR failures: 0
• New failures: 0

No new Flutter test failures introduced by this PR.