fix examples (#1)

Restore working Client connection and positional predict arrays in app.js

Remove credentials field for 100% secure server-side key loading

Implement defensive DOM operations in app.js to fix startup crashes

Align Gradio client predictor parameters and connection imports with official docs

Embed brand logo image, fix blocking client connection and style header buttons

Rename app to Step-3.7-Flash and style header action buttons

Declutter interface for ultra-minimalist and mobile-friendly StepFun Studio design

Redesign playground to match StepFun Studio reference UI

Initialize Step 3.7 Flash Gradio Server application