feat(xai): add Grok OAuth presets for Claude and Claude Desktop

Register the xai_oauth provider type constant and add xAI (Grok) presets
targeting grok-4.5. The Desktop preset routes branded claude-* model IDs
to grok-4.5 upstream so it passes Desktop's third-party model validation.

src/config/claudeDesktopProviderPresets.ts

@@ -56,7 +56,7 @@ export interface ClaudeDesktopProviderPreset {
   mode: "direct" | "proxy";
   apiFormat?: ClaudeDesktopApiFormat;
   modelRoutes?: ClaudeDesktopRoutePreset[];
-  providerType?: "github_copilot" | "codex_oauth";
+  providerType?: "github_copilot" | "codex_oauth" | "xai_oauth";
   requiresOAuth?: boolean;
 
   endpointCandidates?: string[];
@@ -398,6 +398,19 @@ export const claudeDesktopProviderPresets: ClaudeDesktopProviderPreset[] = [
     icon: "openai",
     iconColor: "#000000",
   },
+  {
+    name: "xAI (Grok)",
+    websiteUrl: "https://x.ai/grok",
+    category: "third_party",
+    baseUrl: "https://api.x.ai/v1",
+    mode: "proxy",
+    apiFormat: "openai_responses",
+    providerType: "xai_oauth",
+    requiresOAuth: true,
+    modelRoutes: brandedRoutes("grok-4.5", "grok-4.5", "grok-4.5"),
+    icon: "xai",
+    iconColor: "#000000",
+  },
   {
     name: "DeepSeek",
     websiteUrl: "https://platform.deepseek.com",

src/config/claudeProviderPresets.ts

@@ -60,7 +60,7 @@ export interface ProviderPreset {
   // 供应商类型标识（用于特殊供应商检测）
   // - "github_copilot": GitHub Copilot 供应商（需要 OAuth 认证）
   // - "codex_oauth": OpenAI Codex via ChatGPT Plus/Pro 反代（需要 OAuth 认证）
-  providerType?: "github_copilot" | "codex_oauth";
+  providerType?: "github_copilot" | "codex_oauth" | "xai_oauth";
 
   // 是否需要 OAuth 认证（而非 API Key）
   requiresOAuth?: boolean;
@@ -1269,6 +1269,26 @@ export const providerPresets: ProviderPreset[] = [
     icon: "openai",
     iconColor: "#000000",
   },
+  {
+    name: "xAI (Grok)",
+    websiteUrl: "https://x.ai/grok",
+    settingsConfig: {
+      env: {
+        // The proxy enforces both this origin and the Responses wire format.
+        ANTHROPIC_BASE_URL: "https://api.x.ai/v1",
+        ANTHROPIC_MODEL: "grok-4.5",
+        ANTHROPIC_DEFAULT_HAIKU_MODEL: "grok-4.5",
+        ANTHROPIC_DEFAULT_SONNET_MODEL: "grok-4.5",
+        ANTHROPIC_DEFAULT_OPUS_MODEL: "grok-4.5",
+      },
+    },
+    category: "third_party",
+    apiFormat: "openai_responses",
+    providerType: "xai_oauth",
+    requiresOAuth: true,
+    icon: "xai",
+    iconColor: "#000000",
+  },
   {
     name: "Nvidia",
     websiteUrl: "https://build.nvidia.com",

src/config/constants.ts

@@ -2,6 +2,7 @@
 export const PROVIDER_TYPES = {
   GITHUB_COPILOT: "github_copilot",
   CODEX_OAUTH: "codex_oauth",
+  XAI_OAUTH: "xai_oauth",
 } as const;
 
 // 用量脚本模板类型常量