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

tests/__baseline__/verify-alias.mjs

@@ -16,7 +16,8 @@ const ALIAS_TOKENS = [
   "mistral","pplx","perplexity","together","fireworks","cerebras","cohere","nvidia","nebius",
   "siliconflow","hyp","hyperbolic","dg","deepgram","aai","assemblyai","nb","nanobanana","ch",
   "chutes","ark","volcengine-ark","byteplus","bpm","cursor","vx","vertex","vxp","vertex-partner",
-  "gw","grok-web","pw","perplexity-web","mimo","xiaomi-mimo","xmtp","xiaomi-tokenplan","cf",
+  "gw","grok-web","gcli","gb","grok-build","grok-cli","pw","perplexity-web","mimo","xiaomi-mimo",
+  "xmtp","xiaomi-tokenplan","cf",
   "cloudflare-ai","fal","fal-ai","stability","stability-ai","bfl","black-forest-labs","recraft",
   "topaz","runway","runwayml","jina","jina-ai","polly","aws-polly","bb","blackbox",
 ];