S219: Docs Angular Auth Migration

Migrate docs-angular admin from DOCS_ADMIN_PASS to backend-api JWT; restrict admin to T0/T1; keep docs content open to all users

Session 219: Docs Angular Auth Migration

Replace legacy DOCS_ADMIN_PASS with backend-api JWT authentication
Restrict admin access to T0/T1 roles only (executives, developers, admins, system)
Keep documentation content accessible to any user (based on project selection and privacy level)
Fix content loading 404 in dev and login chunk load failure

Area	Who Can Access	Mechanism
Admin (`/admin`, `/admin/config`, etc.)	Executives, developers, admins, system only	`docsAdminGuard` + backend `RolesGuard`
Documentation content	Any user	`projectSelectedGuard` + `AccessService` (privacy)
Login (`/auth/login`)	Unauthenticated users	`docsLoginPageGuard` redirects if already logged in

Frontend: Switched from AdminAuthService to AuthService (backend-api JWT)
Guards: docsAdminGuard allows executive, developer, admin, system; redirects others to /unauthorized or /auth/login
Backend: Added RolesGuard + @Roles(SystemRoles.EXECUTIVE, SystemRoles.DEVELOPER, SystemRoles.ADMIN, SystemRoles.SYSTEM) on admin endpoints
Login: DocsLoginComponent wraps @auth-ui LoginComponent with showGuestOption: false; eager-loaded to avoid chunk issues

Environment: docsApiUrl: undefined in dev so MarkdownService uses static files; backendApiUrl for login
Proxy: /api → backend-api (3000); /api/admin/docs → docs-admin-proxy (5011)
Split: MarkdownService reads environment.docsApiUrl; DocsApiService uses DOCS_API_URL for admin

404 on content: docsApiUrl was /api → MarkdownService hit backend-api (no /sync/files). Fix: docsApiUrl: undefined in dev → static files
Login chunk failure: Lazy loadComponent for DocsLoginComponent failed. Fix: Use component: DocsLoginComponent (eager-load)

File	Purpose
`apps/docs-angular/src/app/guards/docs-admin.guard.ts`	T0/T1 admin guard
`apps/docs-angular/src/app/pages/docs-login/docs-login.component.ts`	Login wrapper
`apps/docs-angular/src/app/services/dynamic-routes.service.ts`	Routes, guards
`apps/docs-angular/src/environments/environment.ts`	Dev config
`APIs/backend-docs-api/src/app/admin/admin.controller.ts`	RolesGuard on admin
`docs/english/Docs-angular/docs-auth-implementation.md`	Technical doc
`docs/english/Docs-angular/docs-auth-progress-timeline.md`	Non-developer timeline

Decision ID	Question	Chosen
`dev_1773498739714_yxgl509`	How should docs-angular admin auth integrate?	Migrate to backend-api JWT with T0/T1
`dev_1773498742269_t6ldgu7`	Why 404 on /api/sync/files in dev?	Set docsApiUrl undefined for static files
`dev_1773498744346_5003zl9`	Why docs-login chunk load failure?	Eager-load DocsLoginComponent