Docs: update z.ai provider doc

packages/web/src/content/docs/docs/providers.mdx

@@ -761,11 +761,11 @@ https://platform.openai.com/api-keys
 
 ---
 
-### Zhipu AI
+### Z.AI
 
-1. Head over to the [Zhipu API console](https://z.ai/manage-apikey/apikey-list), create an account, and click **Create a new API key**.
+1. Head over to the [Z.AI API console](https://z.ai/manage-apikey/apikey-list), create an account, and click **Create a new API key**.
 
-2. Run `opencode auth login` and select **Zhipu AI**.
+2. Run `opencode auth login` and select **Z.AI**.
 
    ```bash
    $ opencode auth login
@@ -773,12 +773,12 @@ https://platform.openai.com/api-keys
    ┌  Add credential
    │
    ◆  Select provider
-   │  ● Zhipu AI
+   │  ● Z.AI
    │  ...
    └
    ```
 
-3. Enter your Zhipu AI API key.
+3. Enter your Z.AI API key.
 
    ```bash
    $ opencode auth login
@@ -786,7 +786,7 @@ https://platform.openai.com/api-keys
    ┌  Add credential
    │
    ◇  Select provider
-   │  Zhipu AI
+   │  Z.AI
    │
    ◇  Enter your API key
    │  _