Lock-file determinism guarantees re-bakes do not renumber existing
tiles. Atlas_id mismatch is a hard-fail to prevent silent corruption.
Deleted tile IDs move to deleted[] and are not recycled.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Creates the sporel-tool-atlas-baker Node CLI scaffold and the first
phase of the bake pipeline: scan a source directory for *_diffuse.png
files, pair them with optional *_height.png companions, and return
alphabetically-sorted sources for deterministic re-bakes.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>