Resolve const-block conflict in openai_gateway_grok_cache.go: keep #4590 client tool cache constants and #4585 xai-package limit (grokFreeRolling24hTokenLimit removed), add claudeCodeSessionHeader.
Resolve const-block conflict in openai_gateway_grok_cache.go: keep #4590 client tool cache constants and #4585 xai-package limit (grokFreeRolling24hTokenLimit removed), add claudeCodeSessionHeader.