docs: explain browser-origin OAuth discovery in Chinese and English
Add English ChatGPT MCP guide and bilingual navigation
Redact private deployment domains and use official website examples
Record real ChatGPT acceptance and link issue 2280
Document MCP structured result validation troubleshooting
Document unauthenticated MCP discovery probes and diagnostics
Document MCP discovery under API paths and refresh public screenshot
docs: restore MCP client tab layout in tutorial
docs: explain default OAuth discovery with verified browser screenshots
docs: add illustrated ChatGPT MCP API key authorization guide