feat: add Z.ai provider support (general API + coding plan) (#102)

* feat: add Z.ai provider support (general API + coding plan)

Add Z.ai (GLM) as a new LLM provider with two variants:
- `zai`: general API (api.z.ai/api/paas/v4)
- `zai_coding`: coding plan (api.z.ai/api/coding/paas/v4)

Reuses OpenAIProvider — Z.ai API is OpenAI-compatible with Bearer
token auth, SSE streaming, and reasoning_content support.

Includes: store constants, config struct fields, env var loading
(GOCLAW_ZAI_API_KEY, GOCLAW_ZAI_CODING_API_KEY), secret masking,
config + DB registration, onboard wizard, and UI provider types.

Default model: glm-5

Closes #100

* docs: add Z.ai provider entries to providers documentation

cmd/gateway_providers.go

@@ -98,6 +98,24 @@ func registerProviders(registry *providers.Registry, cfg *config.Config) {
 		slog.Info("registered provider", "name", "bailian")
 	}
 
+	if cfg.Providers.Zai.APIKey != "" {
+		base := cfg.Providers.Zai.APIBase
+		if base == "" {
+			base = "https://api.z.ai/api/paas/v4"
+		}
+		registry.Register(providers.NewOpenAIProvider("zai", cfg.Providers.Zai.APIKey, base, "glm-5"))
+		slog.Info("registered provider", "name", "zai")
+	}
+
+	if cfg.Providers.ZaiCoding.APIKey != "" {
+		base := cfg.Providers.ZaiCoding.APIBase
+		if base == "" {
+			base = "https://api.z.ai/api/coding/paas/v4"
+		}
+		registry.Register(providers.NewOpenAIProvider("zai-coding", cfg.Providers.ZaiCoding.APIKey, base, "glm-5"))
+		slog.Info("registered provider", "name", "zai-coding")
+	}
+
 	// Claude CLI provider (subscription-based, no API key needed)
 	if cfg.Providers.ClaudeCLI.CLIPath != "" {
 		cliPath := cfg.Providers.ClaudeCLI.CLIPath
@@ -243,6 +261,18 @@ func registerProvidersFromDB(registry *providers.Registry, provStore store.Provi
 				base = "https://coding-intl.dashscope.aliyuncs.com/v1"
 			}
 			registry.Register(providers.NewOpenAIProvider(p.Name, p.APIKey, base, "qwen3.5-plus"))
+		case store.ProviderZai:
+			base := p.APIBase
+			if base == "" {
+				base = "https://api.z.ai/api/paas/v4"
+			}
+			registry.Register(providers.NewOpenAIProvider(p.Name, p.APIKey, base, "glm-5"))
+		case store.ProviderZaiCoding:
+			base := p.APIBase
+			if base == "" {
+				base = "https://api.z.ai/api/coding/paas/v4"
+			}
+			registry.Register(providers.NewOpenAIProvider(p.Name, p.APIKey, base, "glm-5"))
 		case store.ProviderSuno:
 			// Suno is a media-only provider (music gen). Register as OpenAI-compat
 			// so credentialProvider interface works for API key/base extraction.

cmd/onboard_managed.go

@@ -31,6 +31,8 @@ var defaultPlaceholderProviders = []store.LLMProviderData{
 	{Name: "synthetic", DisplayName: "Synthetic", ProviderType: store.ProviderOpenAICompat, APIBase: "https://api.synthetic.new/openai/v1", Enabled: false},
 	{Name: "alicloud-api", DisplayName: "AliCloud API", ProviderType: store.ProviderDashScope, APIBase: "https://dashscope-intl.aliyuncs.com/compatible-mode/v1", Enabled: false},
 	{Name: "alicloud-sub", DisplayName: "AliCloud Sub", ProviderType: store.ProviderBailian, APIBase: "https://coding-intl.dashscope.aliyuncs.com/v1", Enabled: false},
+	{Name: "zai", DisplayName: "Z.ai API", ProviderType: store.ProviderZai, APIBase: "https://api.z.ai/api/paas/v4", Enabled: false},
+	{Name: "zai-coding", DisplayName: "Z.ai Coding Plan", ProviderType: store.ProviderZaiCoding, APIBase: "https://api.z.ai/api/coding/paas/v4", Enabled: false},
 }
 
 // seedOnboardPlaceholders opens a PG store and seeds disabled placeholder providers