feat(P2): 实现质量保障类5项功能(无障碍/视觉回归/通知渠道/漏洞扫描/灾备)

## 新增功能

### 1. 屏幕阅读器兼容性增强（a11y）
- 无障碍工具库：src/shared/lib/a11y.ts
- aria-live Hook：src/shared/hooks/use-aria-live.ts
- a11y 组件：skip-link/visually-hidden/focus-trap/aria-status
- 增强 UI：table.tsx 系统性 ARIA role，dialog.tsx aria-modal
- 审计文档：docs/accessibility/a11y-audit.md（WCAG 2.1 AA 清单）

### 2. 视觉回归测试
- 测试套件：tests/visual/（homepage + 3 个 dashboard）
- 3 视口（desktop/tablet/mobile）× 2 主题（light/dark）
- 动态元素遮罩，避免误报
- playwright.config.ts 新增 visual-chromium 项目
- 文档：docs/testing/visual-regression.md

### 3. 短信/微信推送渠道集成
- 新模块：src/modules/notifications/
- 4 个渠道：SMS（阿里云/腾讯云）、WeChat（公众号）、Email（SMTP）、In-App
- 分发器按用户偏好并行多渠道发送
- 外部 SDK 动态 import，Mock 模式开发可用
- 文档：docs/notifications/channels.md

### 4. 漏洞扫描 CI 集成
- CI security-scan job：npm audit + Snyk + Trivy FS + OWASP ZAP
- 独立工作流 security.yml：每周一深度扫描 + 容器镜像扫描
- 配置：suppressions.json + .trivyignore
- 本地脚本：security-scan.sh/ps1
- 文档：docs/security/scanning.md（SLA 分级）

### 5. 灾备方案
- 脚本：backup-verify/backup-offsite-sync/dr-drill/failover/health-check
- CI 增强：备份后校验+异地同步，每周灾备演练
- 独立工作流 dr-drill.yml：每周一凌晨 4 点自动演练
- 文档：docs/dr/dr-plan.md（RTO 4h/RPO 24h）+ dr-runbook.md（6 故障场景）

## 验证
- npx tsc --noEmit：0 错误
- npm run lint：0 错误 0 警告

package.json

@@ -15,9 +15,11 @@
     "test:integration": "vitest run --config vitest.config.ts",
     "test:integration:watch": "vitest --config vitest.config.ts",
     "test:integration:coverage": "vitest run --config vitest.config.ts --coverage",
-    "test:e2e": "playwright test",
-    "test:e2e:smoke": "playwright test tests/e2e/smoke-auth.spec.ts",
-    "test:e2e:full-routes": "playwright test tests/e2e/full-route-regression.spec.ts",
+    "test:e2e": "playwright test --project=chromium",
+    "test:e2e:smoke": "playwright test --project=chromium tests/e2e/smoke-auth.spec.ts",
+    "test:e2e:full-routes": "playwright test --project=chromium tests/e2e/full-route-regression.spec.ts",
+    "test:visual": "playwright test --project=visual-chromium",
+    "test:visual:update": "playwright test --project=visual-chromium --update-snapshots",
     "db:create": "npx tsx scripts/create-db.ts",
     "db:seed": "npx tsx scripts/seed.ts",
     "db:generate": "drizzle-kit generate",
@@ -26,8 +28,16 @@
     "db:setup": "npx tsx scripts/create-db.ts && drizzle-kit migrate && npx tsx scripts/seed.ts",
     "audit": "npm audit --audit-level=moderate",
     "audit:report": "npm audit --json > audit-report.json",
+    "security:audit": "npm audit --audit-level=moderate",
+    "security:scan": "bash scripts/security-scan.sh",
     "backup": "bash scripts/backup-db.sh",
-    "restore": "bash scripts/restore-db.sh"
+    "restore": "bash scripts/restore-db.sh",
+    "dr:backup-verify": "bash scripts/backup-verify.sh",
+    "dr:offsite-sync": "bash scripts/backup-offsite-sync.sh",
+    "dr:drill": "bash scripts/dr-drill.sh",
+    "dr:drill:ps1": "powershell -ExecutionPolicy Bypass -File scripts/dr-drill.ps1",
+    "dr:health-check": "bash scripts/health-check.sh",
+    "dr:failover": "bash scripts/failover.sh"
   },
   "dependencies": {
     "@dnd-kit/core": "^6.3.1",