Go: add new provider minimax (#14296)

### What problem does this PR solve?

1. Add new provider minimax
2. Add new command: CHECK INSTANCE 'instance_name' FROM 'provider_name';
```
RAGFlow(user)> check instance 'test' from 'minimax';
SUCCESS
```

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

internal/cli/user_command.go

@@ -1579,6 +1579,46 @@ func (c *RAGFlowClient) ChatToModel(cmd *Command) (ResponseIf, error) {
 	return &result, nil
 }
 
+func (c *RAGFlowClient) CheckProviderConnection(cmd *Command) (ResponseIf, error) {
+	if c.HTTPClient.APIToken == "" && c.HTTPClient.LoginToken == "" {
+		return nil, fmt.Errorf("API token not set. Please login first")
+	}
+
+	if c.ServerType != "user" {
+		return nil, fmt.Errorf("this command is only allowed in USER mode")
+	}
+
+	instanceName, ok := cmd.Params["instance_name"].(string)
+	if !ok {
+		return nil, fmt.Errorf("instance name not provided")
+	}
+
+	providerName, ok := cmd.Params["provider_name"].(string)
+	if !ok {
+		return nil, fmt.Errorf("provider name not provided")
+	}
+
+	url := fmt.Sprintf("/providers/%s/instances/%s/connection", providerName, instanceName)
+
+	resp, err := c.HTTPClient.Request("GET", url, true, "web", nil, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to check provider connection: %w", err)
+	}
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("failed to check provider connection: HTTP %d, body: %s", resp.StatusCode, string(resp.Body))
+	}
+	var result SimpleResponse
+	if err = json.Unmarshal(resp.Body, &result); err != nil {
+		return nil, fmt.Errorf("check provider connection failed: invalid JSON (%w)", err)
+	}
+	if result.Code != 0 {
+		return nil, fmt.Errorf("%s", result.Message)
+	}
+	result.Duration = resp.Duration
+	return &result, nil
+
+}
+
 // UseModel sets the current model for chat
 func (c *RAGFlowClient) UseModel(cmd *Command) (ResponseIf, error) {
 	if c.HTTPClient.APIToken == "" && c.HTTPClient.LoginToken == "" {