Add HyperFrames skills

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011h6NB8JQtfPc6eRCefEzBB

.agents/skills/pr-to-video/scripts/lib/dimensions.mjs

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+// dimensions.mjs — canvas size + caption-band geometry for the video
+// pipeline. Single source of truth = the STORYBOARD frontmatter `format` global
+// ("1920x1080" / "1080x1920" / "1080x1080", or a named orientation). Every
+// script and the index assembler reads the size from here; none hardcodes it.
+
+// Named orientation presets. Square/portrait are 1080-based so they share the
+// long-edge pixel budget with landscape (same render-cost ballpark).
+export const ORIENTATION_PRESETS = {
+  landscape: { width: 1920, height: 1080 }, // 16:9 — default
+  portrait: { width: 1080, height: 1920 }, // 9:16 — reels / shorts / TikTok
+  square: { width: 1080, height: 1080 }, // 1:1 — feed
+};
+
+export const DEFAULT_DIMENSIONS = ORIENTATION_PRESETS.landscape;
+
+function sane(w, h) {
+  return Number.isFinite(w) && Number.isFinite(h) && w >= 240 && h >= 240 && w <= 8192 && h <= 8192;
+}
+
+// Parse a STORYBOARD `format` global into { width, height, source }. Accepts
+// "WxH" (e.g. "1920x1080"; `x` or `×`, any inner spacing) or a named orientation;
+// falls back to landscape so a storyboard with a missing/garbled format still
+// renders (no behavior change vs the old landscape lock).
+export function parseFormat(format) {
+  const s = typeof format === "string" ? format.trim().toLowerCase() : "";
+  if (ORIENTATION_PRESETS[s]) return { ...ORIENTATION_PRESETS[s], source: `orientation=${s}` };
+  const m = s.match(/^(\d+)\s*[x×]\s*(\d+)$/);
+  if (m) {
+    const w = parseInt(m[1] ?? "", 10);
+    const h = parseInt(m[2] ?? "", 10);
+    if (sane(w, h)) return { width: w, height: h, source: "format" };
+  }
+  return { ...DEFAULT_DIMENSIONS, source: "default(landscape)" };
+}
+
+// Caption band geometry, derived from canvas height: the bottom ~16.67% (180px
+// at h=1080). Frame content must end `safetyPx` above the band top. Holds even
+// when captions are disabled (bottom-edge consistency).
+export const CAPTION_BAND_FRACTION = 0.1667;
+export function captionBand(height, safetyPx = 20) {
+  const h = Number.isFinite(height) ? height : DEFAULT_DIMENSIONS.height;
+  const bandHeight = Math.round(h * CAPTION_BAND_FRACTION);
+  const bandTopY = h - bandHeight; // foreground must end at/above this y
+  return { bandHeight, bandTopY, foregroundMaxY: bandTopY - safetyPx };
+}