UI fixes: example list, code scroll, header containment

Fix: move theme+css to gr.Blocks(), not launch()

Fix theme size constants for Gradio 6 (sizes.md → sizes.spacing_md / radius_md)

Premium dark UI: Inter font, indigo accent, card layout, 600px preview

Sprint 4: badge_with_text deterministic template

V2 visual upgrade: lighting presets, contact shadows, RoomEnvironment, OutputPass, colour management

Four targeted fixes: color pass-through, re-render on style/motion, auto-reroll, nested-spheres template

Block 0+2+3: 3B model, curated examples, glow 1.0, auto-frame camera, brighter lights

Add Style/Motion dropdowns, remove mock checkbox, multi-object FEWSHOT

Add Glow toggle and strength slider — user-controllable bloom

Fix thread safety, logging, input validation, pin deps for HF Spaces T4