Optimize baked animation rendering

[agustin-littlehat]

Summary

• make the baked stable-triangle animation path the default and remove the product-facing optimize toggle
• add animated model bench tooling, render stats, and trace-oriented diagnostics
• expose the fast animation path through vanilla, React, and Vue, including imperative mesh updates for framework renderers
• refresh gallery animated assets and prune unused gallery presets/assets

Verification

• pnpm test && pnpm build
• git diff --check
• stale optimize-toggle source scan
• gallery preset asset reference check

Notes

• This PR intentionally includes a large gallery asset cleanup: deleted presets were removed from gallery references, and new animated Poly Pizza assets were added for animation testing.