feat(grok-cli): add Grok CLI / Grok Build provider with OAuth device-code flow (#2502)

New OAuth provider routing through cli-chat-proxy.grok.com (OpenAI Responses
API), distinct from xai (api.x.ai) and grok-web (cookie SSO):

- Registry + GrokCliExecutor: Chat Completions -> Responses transform, CLI
  fingerprint headers, virtual effort models grok-4.5-{low,medium,high}
- OAuth device-code flow (auth.x.ai) with no-PKCE, shared xAI token refresh
- store=false multi-turn continuity via reasoning encrypted_content
- Quota tracker: on-demand window + prepaid balance on dashboard
- Connection test: 402 spending-limit = soft success (auth OK, out of credits)
- Alias/oauth/provider baselines + unit tests

src/app/(dashboard)/dashboard/providers/[id]/page.js

@@ -148,7 +148,10 @@ export default function ProviderDetailPage() {
   const isAnthropicCompatible = isAnthropicCompatibleProvider(providerId);
   const isCompatible = isOpenAICompatible || isAnthropicCompatible;
   const hasDualAuthModes = !isCompatible && isOAuth && supportsApiKeyAuth;
-  const oauthConnectionLabel = providerId === "xai" ? "Grok Build OAuth" : "OAuth";
+  const oauthConnectionLabel =
+    providerId === "xai" ? "Grok Build OAuth"
+    : providerId === "grok-cli" ? "Grok CLI Device Login"
+    : "OAuth";
   const apiKeyConnectionLabel = providerId === "xai" ? "xAI API Key" : "API Key";
   // Resolve suffix "(level)" for a model when a thinking level is picked and the model supports it.
   const resolveThinkingSuffix = (modelId) => {