test: add 30 smoke tests for break detection across SaaS/Admin/Desktop

Layer 1 断裂探测矩阵:
- S1-S6: SaaS API 端到端 (auth/lockout/relay/permissions/billing/knowledge)
- A1-A6: Admin V2 连通性 (login/dashboard/CRUD/knowledge/roles/models)
- D1-D6: Desktop 聊天流 (gateway/kernel/relay/cancel/offline/error)
- F1-F6: Desktop 功能闭环 (agent/hands/pipeline/memory/butler/skills)
- X1-X6: 跨系统闭环 (provider→desktop/disabled user/knowledge/stats/totp/billing)

Also adds: admin-v2 Playwright config, updated spec doc with cross-reference

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/superpowers/specs/2026-04-10-e2e-comprehensive-test-design.md

@@ -3,6 +3,7 @@
 > **目标**: 设计覆盖 SaaS Admin + Tauri Desktop 的全面测试方案，验证所有功能形成闭环工作流
 > **产出物**: 测试设计文档（本文件），指导后续测试执行
 > **范围**: 功能测试 / 集成测试 / 端到端测试 / 数据一致性 / 权限验证
+> **执行策略**: 本文档的详细测试矩阵由 [断裂探测测试方案](../../plans/noble-swinging-lynx.md) 驱动执行——先探测断裂，修复后按本文档做全面回归
 
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