Skip creating partial stats from SSE before the initial REST load
completes, keeping real-time merges limited to existing full stats.
Co-authored-by: Cursor <cursoragent@cursor.com>
Remove dynamic x-anthropic-billing-header lines from Claude system prompts
when translating to OpenAI format to keep prompt prefixes stable and improve
prompt cache hits.
Co-authored-by: Cursor <cursoragent@cursor.com>