Fix detector coverage for generated UI tells

Remove provider gating, share grid-background detection across source and rendered scan paths, and update the detector catalog and tests.\n\nAI-assisted: prepared by Codex at Paul's request.

cli/engine/engines/static-html/detect-html.mjs

@@ -34,7 +34,6 @@ import {
   resolveBackground,
   resolveBorderRadiusPx,
 } from '../../rules/checks.mjs';
-import { filterByProviders } from '../../registry/antipatterns.mjs';
 import { detectText, runTextContentAnalyzers } from '../regex/detect-text.mjs';
 import {
   StaticDocument,
@@ -239,11 +238,10 @@ async function detectHtml(filePath, options = {}) {
     }
   }
 
-  const byProvider = filterByProviders(findings, options.providers);
   // Static-HTML findings carry no line number, so only whole-file
   // `impeccable-disable` directives apply here — exactly the standalone-document
   // waiver this primitive targets. Bypassed by `--no-config` / `--no-inline-ignores`.
-  return options?.inlineIgnores === false ? byProvider : applyInlineIgnores(byProvider, html);
+  return options?.inlineIgnores === false ? findings : applyInlineIgnores(findings, html);
 }
 
 export { checkStaticPageTypography, STATIC_ELEMENT_RULES, detectHtml };