detector: hero pulsing-dot promotion, nav-CTA contrast gap closure, shape-assembled-illustration (56 -> 57)

Item 1 (hero liveness theater):
- pulsing-dot now merges declarations per selector across rule blocks
  (cascade-approximate), descends into media queries, and strips
  prefers-reduced-motion: reduce overrides before the predicate runs.
  Catches the shipped split-block constructions (size in the base rule,
  animation added later or inside a no-preference media block).
- Dots whose element sits inside a header/nav landmark are promoted to
  error severity (string-level landmark ranges in both engines); the
  browser engine additionally promotes dots resting in the first ~900px.
- blinking-cursor findings in the first ~900px or inside header/nav are
  promoted from advisory to warning.
- Per-finding severity overrides now flow through static-html,
  browser-injected serialization, and detect-url.

Item 2 (nav-CTA contrast constructions):
- The a24-opus 01/002 header CTA already fires (specificity cascade +
  oklch + var() all resolved); systematic sweep found two remaining
  escapes and closes both:
  - own gradient background on a SAFE_TAGS element (checkColors styled-
    control exception now treats an own gradient as an own surface,
    contrast measured against the worst stop)
  - ::before/::after full-cover surface (static cascade marks pseudo
    surfaces; browser adapter reads the pseudo computed style) so text is
    measured against the surface the browser actually paints
- nav-cta-constructions fixture locks all eight computable construction
  families; background-image: url() remains unflaggable by design.

Item 3 (shape-assembled-illustration, slop/advisory):
- New rule for large inline SVGs composing a pictorial scene from >= 8
  primitive shapes at >= 200x200 intrinsic size with >= 3 distinct fills.
  Charts (axis labels), stroke-only technical drawings, icons/logos
  (small explicit size), and pattern-tiled backgrounds are exempt.
  1.8 percent fire rate over the 3069-sample eval corpus, all verified
  pictorial scenes; zero fires across val-a22/val-a24.

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

cli/engine/browser/injected/index.mjs

@@ -1222,7 +1222,7 @@ if (IS_BROWSER) {
         return {
           type: f.type || f.id,
           category: ap ? ap.category : 'quality',
-          severity: ap?.severity || 'warning',
+          severity: f.severity || ap?.severity || 'warning',
           detail: f.detail || f.snippet,
           ignoreValue: f.ignoreValue || f.value || '',
           name: ap ? ap.name : (f.type || f.id),
@@ -1489,7 +1489,7 @@ if (IS_BROWSER) {
         ...checkElementClippedOverflowDOM(el).map(f => ({ type: f.id, detail: f.snippet })),
         ...checkElementGptBorderShadowDOM(el).map(f => ({ type: f.id, detail: f.snippet })),
         ...checkElementTextOverflowDOM(el).map(f => ({ type: f.id, detail: f.snippet })),
-        ...checkElementBlinkingCursorDOM(el).map(f => ({ type: f.id, detail: f.snippet })),
+        ...checkElementBlinkingCursorDOM(el).map(f => ({ type: f.id, detail: f.snippet, ...(f.severity ? { severity: f.severity } : {}) })),
         ...checkElementDesignSystemDOM(el, designSystem, designSeen),
       ].filter(f => _ruleOk(f.type));
 
@@ -1588,7 +1588,25 @@ if (IS_BROWSER) {
     }
     const htmlPatternFindings = checkHtmlPatterns(docClone.outerHTML);
     if (htmlPatternFindings.length > 0) {
-      const mapped = htmlPatternFindings.map(f => ({ type: f.id, detail: f.snippet })).filter(f => _ruleOk(f.type));
+      const mapped = htmlPatternFindings.map(f => {
+        const item = { type: f.id, detail: f.snippet };
+        if (f.severity) {
+          item.severity = f.severity;
+        } else if (f.id === 'pulsing-dot' && f.selector) {
+          // The string scan promotes header/nav dots on its own; with a live
+          // layout also promote dots resting in the first ~900px of the page
+          // (the hero region), which the source scan cannot measure.
+          try {
+            const dotEl = document.querySelector(f.selector);
+            if (dotEl) {
+              const rect = dotEl.getBoundingClientRect();
+              const pageTop = rect.top + (window.scrollY || 0);
+              if (pageTop <= 900) item.severity = 'error';
+            }
+          } catch { /* unresolvable selector: keep registry severity */ }
+        }
+        return item;
+      }).filter(f => _ruleOk(f.type));
       pageLevelFindings.push(...mapped);
       addBrowserFindings(groupMap, document.body, mapped);
     }