Fix undefined text error in Markdown chat export

Align vision file limit (max 4) and engine badge to SGLang specs

Set default thinking mode to XHigh

Fix renderSessionsList import in app.js

Fix syntax error in config.js

Update endpoint URL, SGLang 4xH200 specs and README metadata

Fix short_description character limit in README

Update model branding and identifier to Qwen3.8-Flash-Next

Fix banner notification on thinking mode switch

Set default thinking mode to Low

Enable tools/artifacts by default and improve auto naming

Fix syntax errors and enable tools and artifacts

Add Artifacts / Tool Use

Deploy modular static frontend