Freeze SmoothLife model contract and fixtures

plans/07_multiscale_backend.md

@@ -12,7 +12,7 @@ Macrosteps 00–06 complete.
 
 - Mandatory scope is three scales on a periodic 2-D domain.
 - The historical 1-D/3-D infrastructure was nonfunctional because integration existed only in 2-D; do not claim support there.
-- Generalizing to `n` scales is acceptable internally, but imported fixtures remain exactly three.
+- Generalizing to `n` scales is acceptable internally, but mandatory product presets and contract fixtures remain exactly three scales.
 
 ## Phase 7.1 — Typed semantic model
 
@@ -31,7 +31,7 @@ Composition
 
 Each `ScaleConfig` owns radius/ratios, `dt`, dynamics, and rule. Dimension/shape belongs to the common domain, not each scale.
 
-Validate positive geometry, valid rules, exactly three scales for imported presets, growth/relaxation dynamics only, and descending/nested scales for chained bands. Nonnested bands are defined but produce a warning explaining their meaning.
+Validate positive geometry, valid rules, exactly three scales, growth/relaxation dynamics only, and descending/nested scales for chained bands. Nonnested bands are defined but produce a warning explaining their meaning.
 
 ## Phase 7.2 — Neighborhood evaluation
 
@@ -145,13 +145,13 @@ Provide:
 - combined increment and clamp-stage views;
 - scale-color overlay and radial-band diagram;
 - clear validation for unsupported discrete dynamics and warnings for nonnested chained radii;
-- imported triplet preset browser preserving group identity.
+- newly authored three-scale preset browser with stable preset identity.
 
 ## Deliverables
 
 - CPU and GPU multiscale 2-D backend.
 - All six kernel/composition combinations for growth/relaxation, using either selectable GPU FFT algorithm.
-- Per-scale inspectors and imported four legacy triplet groups.
+- Per-scale inspectors and newly authored deterministic multiscale presets.
 
 ## Exit gate