chore(lint): keep the fallow audit gate green

Extract rootClassStyledSelectors so the subcomposition_root_styled_by_class
rule drops below the complexity threshold, and ignore the music-to-video
reference HTML (template + motion-primitive materials forked by path, not
import-graph reachable) — same treatment as motion-graphics/grounding.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.fallowrc.jsonc

@@ -59,6 +59,9 @@
     // prose), not import-graph reachable.
     "skills/motion-graphics/grounding/**",
     "skills/motion-graphics/categories/**",
+    // Agent-invoked reference materials (template + motion-primitive HTML, catalogs),
+    // forked by path by the frame-worker per SKILL.md prose, not import-graph reachable.
+    "skills/music-to-video/references/**",
     // Bundled @font-face data (read at runtime via fs.readFileSync, invisible
     // to the import graph) + its manual rebuild tool.
     "skills/**/fonts/**",

packages/core/src/lint/rules/composition.ts

@@ -1,4 +1,4 @@
-import type { LintContext, HyperframeLintFinding } from "../context";
+import type { LintContext, HyperframeLintFinding, ExtractedBlock } from "../context";
 import { findHtmlTag, readAttr, readJsonAttr, stripJsComments, truncateSnippet } from "../utils";
 import { COMPOSITION_VARIABLE_TYPES } from "../../core.types";
 
@@ -63,6 +63,19 @@ function leftmostCompoundClasses(selector: string): string[] {
   return (leftmost.match(/\.([\w-]+)/g) ?? []).map((c) => c.slice(1));
 }
 
+// Distinct selectors across all <style> blocks whose leftmost compound keys off one
+// of the root element's own classes — the ones that break under id-scoping.
+function rootClassStyledSelectors(styles: ExtractedBlock[], rootClasses: string[]): string[] {
+  const offenders: string[] = [];
+  for (const style of styles) {
+    for (const selector of extractCssSelectors(style.content)) {
+      const hitsRoot = leftmostCompoundClasses(selector).some((c) => rootClasses.includes(c));
+      if (hitsRoot && !offenders.includes(selector)) offenders.push(selector);
+    }
+  }
+  return offenders;
+}
+
 export const compositionRules: Array<(ctx: LintContext) => HyperframeLintFinding[]> = [
   // invalid_capture_path — catches ../capture/ in src/href attributes and scripts.
   // Sub-compositions live in compositions/ but are served relative to the project
@@ -624,13 +637,7 @@ export const compositionRules: Array<(ctx: LintContext) => HyperframeLintFinding
     const rootClasses = (readAttr(rootTag.raw, "class") || "").split(/\s+/).filter(Boolean);
     if (rootClasses.length === 0) return [];
 
-    const offenders: string[] = [];
+    const offenders = rootClassStyledSelectors(styles, rootClasses);
-    for (const style of styles) {
-      for (const selector of extractCssSelectors(style.content)) {
-        const hitsRoot = leftmostCompoundClasses(selector).some((c) => rootClasses.includes(c));
-        if (hitsRoot && !offenders.includes(selector)) offenders.push(selector);
-      }
-    }
     if (offenders.length === 0) return [];
 
     const example = offenders.slice(0, 3).join(", ");