fix: resolve deployment API errors and enable E2E deployment flow

Backend fixes:
- instance_dto: add Version field with Normalize() to support both 'version'
  and 'tag' field names from frontend
- instance_handler: add version empty validation before creating instance
- authz.go: fix unused variable compilation error
- registry_repository: fix GetByID/GetByName to use correct DB schema
  (add workspace_id, owner_id, is_shared fields); decrypt password
  gracefully when encryption key mismatches instead of returning error

Frontend:
- charts/page: add Template and Storage dropdown selectors to Deploy Modal

Testing:
- add e2e_test.py: 5-step Playwright E2E test (admin login → create
  workspace → create user → user login → deploy chart)
- add tasks/lesson.md: document 4 bug root causes and fixes
- add tasks/todo.md: track implementation progress
- add PLAN_E2E_DEPLOYMENT.md: comprehensive implementation plan

Verification: confirmed deployment creates instance with status=deployed,
chart downloads from Harbor OCI to /tmp/charts/, Helm release deploys to K8s

tasks/todo.md

@@ -0,0 +1,45 @@
+# OCDP E2E 部署流程 - 任务追踪
+
+## 状态总览
+
+- ✅ Phase 1: 诊断部署问题
+- ✅ Phase 2: 完善 Admin 用户管理 UI
+- ✅ Phase 3: 增强 Deploy Modal（Template/Storage 选择器）
+- ✅ Phase 4: E2E 端到端验证
+- ✅ Bug Fix: frontend version → backend req.Tag 字段映射
+- ✅ Bug Fix: registry 解密失败 graceful fallback
+- 🔄 Phase 5: Values Template 版本管理 (P2)
+- 🔄 Phase 6: Storage 分层配置 (P2)
+
+## 当前里程碑
+
+核心部署流程已打通（2026-04-16）：
+- Admin 创建 workspace → 创建 user ✓
+- User 登录 → 浏览 Charts → 部署成功 → status=deployed ✓
+- Chart 从 Harbor OCI 下载到 /tmp/charts/ ✓
+- Helm release 部署到 K8s 集群 ✓
+
+## 待办事项
+
+### Phase 5: Values Template 版本管理
+- [ ] 每次更新创建新版本
+- [ ] 查看版本历史
+- [ ] 回滚到历史版本
+- 关键文件: `backend/internal/domain/service/values_template_service.go`, `frontend/src/app/templates/page.tsx`
+
+### Phase 6: Storage 分层配置
+- [ ] Cluster-level 默认存储
+- [ ] Workspace-level 存储覆盖
+- [ ] User Override 最高优先级
+- 关键文件: `backend/internal/domain/service/storage_service.go`, `frontend/src/app/storage/page.tsx`
+
+## 完成清单
+
+- [x] Backend: instance_dto.go - 添加 Version 字段，Normalize() 兼容 version/tag
+- [x] Backend: instance_handler.go - 添加 version 空值校验
+- [x] Backend: authz.go - 修复 unused variable 编译错误
+- [x] Backend: registry_repository.go - 修复 GetByID/GetByName schema 字段不匹配
+- [x] Backend: registry_repository.go - 解密失败时返回空密码而非错误
+- [x] Frontend: charts/page.tsx - 添加 Template 和 Storage 下拉选择器
+- [x] Tests: e2e_test.py - 完整 5 步 E2E 测试
+- [x] Docs: tasks/lessons.md - 记录 4 个 Bug 的根因和修复