Admin API edge cases (empty password, blocked user session)

### 👟 Reproduction steps **Environment:** - `appwrite/appwrite:latest` (1.9.0) - MariaDB 10.11 - Redis (no auth) - Database worker (`worker-databases` command) - Env vars: `_APP_OPTIONS_ABUSE=disabled`, `_APP_OPTIONS_FORCE_HTTPS=disabled`, `_APP_DOMAIN=appwrite` **Setup:** Bootstrap an Appwrite instance with an admin account, project, and API key with `users.read` + `users.write` scopes: 1. Register an admin account via `POST /v1/account` (project: `console`) 2. Create admin session, team, and project 3. Create an API key with scopes: `["users.read", "users.write"]` 4. Create a test user via `POST /v1/users` with a known password (e.g., `OriginalPass123!`) **Control — normal password update:** ``` PATCH /v1/users/{userId}/password Content-Type: application/json X-Appwrite-Project: {projectId} X-Appwrite-Key: {apiKey} { "password": "NewValidPassword456!" } ``` Returns 200 with the user object. The `hash` field shows `argon2` and `passwordUpdate` timestamp is updated. This confirms the endpoint works normally for non-empty passwords. **Bug 1 — empty string password:** ``` PATCH /v1/users/{userId}/password Content-Type: application/json X-Appwrite-Project: {projectId} X-Appwrite-Key: {apiKey} { "password": "" } ``` Returns **200** with response body containing both `"password": ""` and `"hash": "argon2"`. **Verification — get user after empty password:** ``` GET /v1/users/{userId} X-Appwrite-Project: {projectId} X-Appwrite-Key: {apiKey} ``` Returns 200. The `passwordUpdate` timestamp has been updated and `hash` shows `argon2`, confirming the empty string was hashed and stored. **Bug 2 — session creation for blocked user:** First, block the user: ``` PATCH /v1/users/{userId}/status Content-Type: application/json X-Appwrite-Project: {projectId} X-Appwrite-Key: {apiKey} { "status": false } ``` Returns 200 with `"status": false`. Then create a session for the blocked user: ``` POST /v1/users/{userId}/sessions Content-Type: application/json X-Appwrite-Project: {proje…