docs: update documentation to OKF v0.1 format

docs/architecture/backend-modules.md

@@ -23,12 +23,13 @@ also registers two global providers:
 | `DatabaseModule` | `backend/src/database/database.module.ts`     | Configures TypeORM with `better-sqlite3`, registers entities, runs migrations, enforces WAL.    |
 | `CommonModule`   | `backend/src/common/common.module.ts`         | Provides shared services (CSRF middleware class, backoff, registration rate limit, SSE hub, theme loader, etc.). |
 | `SettingsModule` | `backend/src/modules/settings/settings.module.ts` | Exposes `SettingsService` (get/set/getAll over `setting` table).                              |
-| `AuthModule`     | `backend/src/modules/auth/auth.module.ts`     | `AuthController` (`/api/v1/auth/*`) + `AuthService` (login/refresh/logout/register-first-admin).|
+| `AuthModule`     | `backend/src/modules/auth/auth.module.ts`     | `AuthController` (`/api/v1/auth/*`) + `AuthService` (login/refresh/logout/register-first-admin + public `register`). Imports `SettingsModule` so the public-register flow can read the `registrationsEnabled` flag. |
 | `UsersModule`    | `backend/src/modules/users/users.module.ts`   | `UsersController` (`/api/v1/auth/register-first-admin`) + `UsersService` (last-admin invariant). |
 | `SetupModule`    | `backend/src/modules/setup/setup.module.ts`   | `SetupController` (`POST /api/v1/setup/create-admin`) + `SetupService`. Returns 409 `SYSTEM_INITIALIZED` once any admin exists; serializes concurrent first-admin attempts via an in-process promise chain. |
 | `SystemModule`   | `backend/src/modules/system/system.module.ts` | `SystemController` (`/api/v1/bootstrap`, `/event/status`, SSE streams) + `SystemService`.       |
 | `AdminModule`    | `backend/src/modules/admin/admin.module.ts`   | `AdminController` (`/api/v1/admin/users*`) + `AdminService`. Gated by `AdminGuard` + `@Roles('admin')`. |
 | `UploadsModule`  | `backend/src/modules/uploads/uploads.module.ts` | `UploadsController` (`/api/v1/uploads/*`). Admin-only multipart.                            |
+| `BlogModule`     | `backend/src/modules/blog/blog.module.ts`     | `BlogController` (`GET /api/v1/blog/posts`) + `BlogService` (lists `status='published'` rows). |
 | `FrontendModule` | `backend/src/frontend/frontend.module.ts`     | Registers `SpaFallbackMiddleware` and the uploads static helper.                              |
 
 # Controllers
@@ -41,6 +42,7 @@ also registers two global providers:
 | `AdminController`      | `/api/v1/admin`         | Admin only   | `backend/src/modules/admin/admin.controller.ts`              |
 | `SystemController`     | `/api/v1`               | Public       | `backend/src/modules/system/system.controller.ts`            |
 | `UploadsController`    | `/api/v1/uploads`       | Admin only   | `backend/src/modules/uploads/uploads.controller.ts`          |
+| `BlogController`       | `/api/v1/blog`          | Public       | `backend/src/modules/blog/blog.controller.ts`               |
 
 # Common services