feat: Add Z.AI provider support with all available models

Add Z.AI (z.ai) as a new LLM provider, the international platform by
Zhipu AI. This includes automatic endpoint routing between the standard
API and the dedicated Coding API based on model name.

- Standard endpoint: https://api.z.ai/api/paas/v4
- Coding endpoint:   https://api.z.ai/api/coding/paas/v4

Supported models: GLM-5, GLM-4.7, GLM-4.6, GLM-4.5, GLM-4.6V,
GLM-4.5V, GLM-OCR, GLM-Image, CogView-4, CogVideoX-3, GLM-ASR-2512,
AutoGLM-Phone-Multilingual, Vidu-Q1, Vidu-2.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

config/config.example.json

@@ -91,6 +91,10 @@
       "api_key": "YOUR_ZHIPU_API_KEY",
       "api_base": ""
     },
+    "zai": {
+      "api_key": "YOUR_ZAI_API_KEY",
+      "api_base": ""
+    },
     "gemini": {
       "api_key": "",
       "api_base": ""

pkg/config/config.go

@@ -172,6 +172,7 @@ type ProvidersConfig struct {
 	OpenRouter    ProviderConfig `json:"openrouter"`
 	Groq          ProviderConfig `json:"groq"`
 	Zhipu         ProviderConfig `json:"zhipu"`
+	ZAI           ProviderConfig `json:"zai"`
 	VLLM          ProviderConfig `json:"vllm"`
 	Gemini        ProviderConfig `json:"gemini"`
 	Nvidia        ProviderConfig `json:"nvidia"`
@@ -299,6 +300,7 @@ func DefaultConfig() *Config {
 			OpenRouter:   ProviderConfig{},
 			Groq:         ProviderConfig{},
 			Zhipu:        ProviderConfig{},
+			ZAI:          ProviderConfig{},
 			VLLM:         ProviderConfig{},
 			Gemini:       ProviderConfig{},
 			Nvidia:       ProviderConfig{},
@@ -396,6 +398,9 @@ func (c *Config) GetAPIKey() string {
 	if c.Providers.Zhipu.APIKey != "" {
 		return c.Providers.Zhipu.APIKey
 	}
+	if c.Providers.ZAI.APIKey != "" {
+		return c.Providers.ZAI.APIKey
+	}
 	if c.Providers.Groq.APIKey != "" {
 		return c.Providers.Groq.APIKey
 	}

pkg/providers/http_provider.go

@@ -56,7 +56,7 @@ func (p *HTTPProvider) Chat(ctx context.Context, messages []Message, tools []Too
 	// Strip provider prefix from model name (e.g., moonshot/kimi-k2.5 -> kimi-k2.5)
 	if idx := strings.Index(model, "/"); idx != -1 {
 		prefix := model[:idx]
-		if prefix == "moonshot" || prefix == "nvidia" {
+		if prefix == "moonshot" || prefix == "nvidia" || prefix == "zai" {
 			model = model[idx+1:]
 		}
 	}
@@ -277,6 +277,19 @@ func CreateProvider(cfg *config.Config) (LLMProvider, error) {
 					apiBase = "https://open.bigmodel.cn/api/paas/v4"
 				}
 			}
+		case "zai", "z.ai":
+			if cfg.Providers.ZAI.APIKey != "" {
+				apiKey = cfg.Providers.ZAI.APIKey
+				apiBase = cfg.Providers.ZAI.APIBase
+				proxy = cfg.Providers.ZAI.Proxy
+				if apiBase == "" {
+					if strings.Contains(lowerModel, "coding") {
+						apiBase = "https://api.z.ai/api/coding/paas/v4"
+					} else {
+						apiBase = "https://api.z.ai/api/paas/v4"
+					}
+				}
+			}
 		case "gemini", "google":
 			if cfg.Providers.Gemini.APIKey != "" {
 				apiKey = cfg.Providers.Gemini.APIKey
@@ -377,7 +390,19 @@ func CreateProvider(cfg *config.Config) (LLMProvider, error) {
 				apiBase = "https://generativelanguage.googleapis.com/v1beta"
 			}
 
-		case (strings.Contains(lowerModel, "glm") || strings.Contains(lowerModel, "zhipu") || strings.Contains(lowerModel, "zai")) && cfg.Providers.Zhipu.APIKey != "":
+		case (strings.Contains(lowerModel, "glm") || strings.Contains(lowerModel, "cogview") || strings.Contains(lowerModel, "cogvideo") || strings.Contains(lowerModel, "autoglm") || strings.Contains(lowerModel, "vidu")) && cfg.Providers.ZAI.APIKey != "":
+			apiKey = cfg.Providers.ZAI.APIKey
+			apiBase = cfg.Providers.ZAI.APIBase
+			proxy = cfg.Providers.ZAI.Proxy
+			if apiBase == "" {
+				if strings.Contains(lowerModel, "coding") {
+					apiBase = "https://api.z.ai/api/coding/paas/v4"
+				} else {
+					apiBase = "https://api.z.ai/api/paas/v4"
+				}
+			}
+
+		case (strings.Contains(lowerModel, "glm") || strings.Contains(lowerModel, "zhipu")) && cfg.Providers.Zhipu.APIKey != "":
 			apiKey = cfg.Providers.Zhipu.APIKey
 			apiBase = cfg.Providers.Zhipu.APIBase
 			proxy = cfg.Providers.Zhipu.Proxy