shader_pack.rs reads shaderpacks/<pack>/pack.toml, the player's option
values (shaderpacks/<pack>.txt) and each composite stage's WGSL, puts
the api 1 prelude (bindings, the Frame uniform, depth helpers) before
it and has naga parse and validate it, with errors pointing into the
pack's own file. Options are WGSL override constants. A file stamp
tells when the pack was edited, for hot reload. Nothing draws with it
yet. examples/shaderpacks/horizon-sample is the MIT sample pack.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Ludovic Marie