Capture & emission fidelity wave: dotLottie support, scroll-state isolation, authored-geometry trust, honest quality scoring

Capture:
- Preserve real asset extensions (.lottie no longer truncated); extract the
  default animation JSON from dotLottie ZIP containers at materialization
  (minimal built-in ZIP reader, no new deps)
- Reset scroll + settle before every viewport snapshot so scroll-linked
  styles can't bake into captured computed values
- Marquee detection now requires content overflow (>1.35x), sustained
  velocity across separated windows, scroll independence (jiggle test), and
  genuine content repetition — kills scroll-settle-lerp false positives
- Sizing probe trusts authored explicit heights (px/vh/calc) over circular
  parent/child reflow verdicts, fixing dropped 100vh heroes

Normalize/generate:
- Canonicalize identity transforms to "none" per viewport; emit explicit
  transform resets across bands when any band has a real transform
- DittoLottie keeps the captured placeholder until DOMLoaded; failed loads
  no longer blank the container
- mx-auto only for true auto-margin centering; literal per-band margins are
  preserved (fixes full-bleed regressions)
- Spacing-scale snap tightened to 0.25px (3.5px stays p-[3.5px]); emit
  whitespace-nowrap for wrap-vulnerable single-line text leaves
- Grid recipes no longer override captured track counts or column spans;
  responsive re-flow plans apply only when geometry agrees

Quality scoring:
- Rewritten 6-dimension rubric (payload, decomposition, duplication,
  semantics, hygiene, runtime) with catastrophe caps and per-dimension
  reporting; thresholds are documented calibration guides

218 tests pass (74 new), typecheck clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

compiler/test/tailwind.test.ts

@@ -1,6 +1,6 @@
 import { describe, it } from "node:test";
 import assert from "node:assert/strict";
-import { declToUtil } from "../src/generate/tailwind.js";
+import { declToUtil, snapBase } from "../src/generate/tailwind.js";
 
 // Zero-value gating. A named `-0` step only exists for props on Tailwind's spacing (or numeric)
 // scales; for the rest the class compiles to NOTHING — a silent no-op that ships the wrong style
@@ -41,3 +41,33 @@ describe("declToUtil zero values", () => {
     assert.equal(declToUtil("letter-spacing", "-0.5px"), "tracking-[-0.5px]");
   });
 });
+
+// BUG B — the spacing-scale snap must only fire when a value lands ESSENTIALLY ON a step (≤0.25px).
+// The scale is 2px-granular (`p-0.5`=2px, `p-1.5`=6px), so 3.5px is BETWEEN steps — snapping it up to
+// p-1 (4px) adds +0.5px per side, which accumulates across a fixed-width flex row until items overflow
+// and wrap. On-step values (2px→p-0.5, 4px→p-1) still snap.
+describe("snapBase spacing-scale snapping", () => {
+  it("keeps a between-steps value arbitrary (3.5px does NOT snap to p-1)", () => {
+    assert.equal(snapBase("p-[3.5px]"), "p-[3.5px]");
+  });
+
+  it("does not snap the same sub-step delta on other spacing props", () => {
+    assert.equal(snapBase("pl-[3.5px]"), "pl-[3.5px]");
+    assert.equal(snapBase("gap-[3.5px]"), "gap-[3.5px]");
+    assert.equal(snapBase("mt-[13.5px]"), "mt-[13.5px]"); // between p-3 (12px) and p-3.5 (14px)
+  });
+
+  it("still snaps a value that sits on a 0.5-step (2px → p-0.5, 6px → p-1.5)", () => {
+    assert.equal(snapBase("p-[2px]"), "p-0.5");
+    assert.equal(snapBase("p-[6px]"), "p-1.5");
+  });
+
+  it("still snaps a near-exact on-step value within the tight budget (3.98px → p-1)", () => {
+    assert.equal(snapBase("p-[3.98px]"), "p-1");
+  });
+
+  it("leaves an already-clean scale utility unchanged and snaps 16px → mx-4", () => {
+    assert.equal(snapBase("p-1"), "p-1");
+    assert.equal(snapBase("mx-[16px]"), "mx-4");
+  });
+});