feat: polish PSP UI demos and rendering

[doodlewind]

Summary

• Optimizes rounded/shadow rendering and fixes PSP scissor handling so filled bars render correctly on hardware/PPSSPP.
• Polishes the demo UI surface: theme-linked Settings colors, faster switches, Mission Control LEFT/RIGHT tabs with staggered Systems reveal, and no default-gray color fades on detail panels.
• Adds SVG asset baking with supersampled alpha coverage, then uses baked spinner frames in Hero and Game Library loading states.
• Updates WASM and PPSSPP golden coverage, including early frames for Cards opening and Library loading to guard against the visual regressions.

Validation

• cargo test --manifest-path core/Cargo.toml
• bunx tsc --noEmit
• bun run test
• bun test/golden.ts
• UPDATE=1 bun run e2e
• bun run e2e
• bun scripts/psp-all.ts --release
• Synced release EBOOTs to /Volumes/NO NAME/PSP/GAME and byte-compared each copied file with local dist/psp/PSP/GAME output.