Fixes a real gap left over from Phase 11: mesh.rs's 3D mesher was still
using the hand-picked flat palette instead of texture-averaged colors.
Adds worker/src/atlas.rs to pack downloaded block textures into a single
PNG atlas + UV rect map, threads tile-relative UV and atlas-rect buffers
through the mesh binary format (v2, hard break — meshes are a
regenerable render cache), serves the atlas from MinIO via two new api
routes, and adds a custom Babylon shader that falls back to flat vertex
colors per-fragment for untextured quads. glTF export intentionally
stays vertex-color-only (documented reasoning in gltf-export.js) since
standard glTF materials can't express that same per-fragment fallback.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015tKdPZt78zbPUZMXWzKEKt
octoturgeandClaude Sonnet 5
6ad8051eae