feat: add support for GitHub Models provider

- Introduced environment variable CLAUDE_CODE_USE_GITHUB to enable GitHub Models.
- Added checks for GITHUB_TOKEN or GH_TOKEN for authentication.
- Updated base URL handling to include GitHub Models default.
- Enhanced provider detection and error handling for GitHub Models.
- Updated relevant functions and components to accommodate the new provider.

src/utils/model/providers.ts

@@ -1,20 +1,29 @@
 import type { AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS } from '../../services/analytics/index.js'
 import { isEnvTruthy } from '../envUtils.js'
 
-export type APIProvider = 'firstParty' | 'bedrock' | 'vertex' | 'foundry' | 'openai' | 'gemini'
+export type APIProvider =
+  | 'firstParty'
+  | 'bedrock'
+  | 'vertex'
+  | 'foundry'
+  | 'openai'
+  | 'gemini'
+  | 'github'
 
 export function getAPIProvider(): APIProvider {
   return isEnvTruthy(process.env.CLAUDE_CODE_USE_GEMINI)
     ? 'gemini'
-    : isEnvTruthy(process.env.CLAUDE_CODE_USE_OPENAI)
-      ? 'openai'
-      : isEnvTruthy(process.env.CLAUDE_CODE_USE_BEDROCK)
-        ? 'bedrock'
-        : isEnvTruthy(process.env.CLAUDE_CODE_USE_VERTEX)
-          ? 'vertex'
-          : isEnvTruthy(process.env.CLAUDE_CODE_USE_FOUNDRY)
-            ? 'foundry'
-            : 'firstParty'
+    : isEnvTruthy(process.env.CLAUDE_CODE_USE_GITHUB)
+      ? 'github'
+      : isEnvTruthy(process.env.CLAUDE_CODE_USE_OPENAI)
+        ? 'openai'
+        : isEnvTruthy(process.env.CLAUDE_CODE_USE_BEDROCK)
+          ? 'bedrock'
+          : isEnvTruthy(process.env.CLAUDE_CODE_USE_VERTEX)
+            ? 'vertex'
+            : isEnvTruthy(process.env.CLAUDE_CODE_USE_FOUNDRY)
+              ? 'foundry'
+              : 'firstParty'
 }
 
 export function usesAnthropicAccountFlow(): boolean {