Generated-code hygiene: listener cleanup, shared cn(), whitespace collapse, probe stripping, sub-pixel snapping, clone-origin metadata, dependency pinning

- DittoWire/Accordion/DropdownMenu runtime templates: AbortController-based
  listener cleanup, idempotent effects, orphan panel removal on unmount
- Emit a single src/lib/utils.ts cn() instead of a copy per component file
- Collapse captured whitespace runs under white-space:normal (pre* preserved)
- Tag source-injected font-metric probe nodes at capture; drop them from IR
- Snap sub-pixel arbitrary lengths (integer within 0.1px, else 1 decimal)
- Emit SITE_ORIGIN (src/lib/site.ts, env-overridable): sitemap/robots/
  canonical/og:url/JSON-LD resolve against the clone's own origin instead of
  the source domain
- Pin lottie-web in generated package.json whenever DittoLottie is emitted

144 tests pass (21 new), typecheck clean.

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

compiler/src/generate/css.ts

@@ -298,7 +298,10 @@ export type WidthPlan = { kind: "fixed" } | { kind: "auto" } | { kind: "percent"
 const PLAN_FIXED: WidthPlan = { kind: "fixed" };
 
 const pf = (v: string | undefined): number => { const n = parseFloat(v ?? ""); return Number.isFinite(n) ? n : 0; };
-const fmtPx = (n: number): string => `${Math.round(n * 1000) / 1000}px`;
+// Snap sub-pixel geometry: integer when within 0.1px (measurement jitter), else at most 1 decimal
+// — matching the Tailwind arbitrary-length rounding (tailwind.ts:snapLen) so CSS and utility output
+// agree and frozen sub-pixel noise (204.797px) never ships. Transforms/border widths format elsewhere.
+const fmtPx = (n: number): string => `${(Math.abs(n - Math.round(n)) < 0.1 ? Math.round(n) : Math.round(n * 10) / 10)}px`;
 const viewportHeightFor = (vp: number): number => CAPTURE_VIEWPORT_HEIGHTS[vp] ?? Math.round(vp * 0.66);
 
 type GeometryPlan = {