Every AI tool just got smarter: default model bumped to Claude Sonnet 5

The best model available today is not the best model available six months ago, and pinning a tool to an old provider version is a silent quality regression. We introduced a shared model-defaults module (lib/model-defaults.ts) so every AI tool inherits from a single source of truth. When a provider ships a new best-in-class model, bumping the string here propagates everywhere.

What changed

• Anthropic text default: Claude Sonnet 4.6 to Claude Sonnet 5 across Godot script gen, Unity script gen, particle designer, lore, translate, moderation triage, and prompt-to-browser-game streaming
• Moodboard image model: Stability AI SDXL to Black Forest Labs FLUX 1.1 Pro (dramatically better concept-art quality)
• 3D-preview seed image: SDXL to FLUX 1.1 Pro (the input image quality drives the final mesh quality)

Every constant honors an environment variable override, so a deploy can pin an older model per tool without a code change if needed.