docs: clarify Address JWT vs User JWT and reorganize API menu (#914)

- Add warning notes in new-address-api and mail-api docs
- Explain the difference between Address JWT and User JWT
- Create dedicated 'API Endpoints' section in sidebar
- Update both zh and en documentation

Refs #910

vitepress-docs/docs/en/guide/feature/mail-api.md

@@ -131,6 +131,14 @@ print(response.json())
 
 ## User Mail API
 
+::: warning Note: User JWT vs Address JWT
+This endpoint uses **User JWT** (obtained via `/user_api/login` or `/user_api/register`), with `x-user-token` header.
+
+**Do not confuse with Address JWT**:
+- Address JWT uses `Authorization: Bearer <jwt>` to access `/api/*` endpoints
+- User JWT uses `x-user-token: <jwt>` to access `/user_api/*` endpoints
+:::
+
 Supports `address` filter
 
 ```python

vitepress-docs/docs/en/guide/feature/new-address-api.md

@@ -1,5 +1,19 @@
 # Create New Email Address API
 
+::: warning Note: Address JWT vs User JWT
+This page describes **Address JWT**, which is different from **User JWT**:
+
+- **Address JWT**: Returned when creating a mailbox via `/api/new_address` or `/admin/new_address`
+  - Use `Authorization: Bearer <jwt>` header
+  - Access `/api/*` endpoints (view mails, delete mails, etc.)
+
+- **User JWT**: Obtained via `/user_api/login` or `/user_api/register`
+  - Use `x-user-token: <jwt>` header
+  - Access `/user_api/*` endpoints (user account management)
+
+**Do not confuse these two JWT types!**
+:::
+
 ## Create Email Address via Admin API
 
 This is a `python` example using the `requests` library to send emails.