Add HyperFrames skills (from heygen-com/hyperframes, Apache-2.0)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FXVsD1DgdzZLiPuwtKzMSY

.claude/skills/media-use/scripts/lib/transcriptCutFade.mjs

@@ -0,0 +1,21 @@
+function round3(n) {
+  return Math.round(Number(n) * 1000) / 1000;
+}
+
+// 30ms in/out ramps kill the click at every concat boundary. A segment shorter
+// than 4x the ramp would spend its whole length fading, so scale down there and
+// skip entirely on a degenerate one. fadeIn/fadeOut are false at the export's
+// own true start/end, where there is no splice to smooth.
+export function fadeFilterFor(durationSeconds, { fadeIn, fadeOut }) {
+  if (!fadeIn && !fadeOut) return null;
+  const FADE_SECONDS = 0.03;
+  if (!Number.isFinite(durationSeconds) || durationSeconds <= 0.01) return null;
+  const d = Math.min(FADE_SECONDS, durationSeconds / 4);
+  const parts = [];
+  if (fadeIn) parts.push(`afade=t=in:st=0:d=${round3(d)}`);
+  if (fadeOut) {
+    const out = round3(durationSeconds - d);
+    if (out > 0) parts.push(`afade=t=out:st=${out}:d=${round3(d)}`);
+  }
+  return parts.length ? parts.join(",") : null;
+}