fix(registry): liberal emoji-pop brand colors, weight-shift fit fixes, 8192 clamp

- caption-emoji-pop: shadowForColor now builds its glow via color-mix()
  instead of hex-pair slicing, so the strict 6-digit brand-color gate is
  gone — any CSS color the sibling templates accept (#fff, rgb(), named)
  now renders instead of silently falling back to the default palette

- caption-weight-shift: fitFontSize now sizes against the WIDEST split
  line rather than the joined group text (two-line groups no longer shrink
  unnecessarily), and avoidSingleWordGroups' merges re-check fitsInTwoLines
  like makeGroups' first pass does (merged groups can no longer overflow
  the split budget)

- all 5: hfApplyStageConfig clamps resolution to the published validator's
  <=8192 bound (validator is optional pre-flight; unbounded stages OOM
  render workers), and fit floors carry a comment documenting that the
  minimum size is returned unverified by design

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

registry/components/caption-emoji-pop/caption-emoji-pop.html

@@ -229,8 +229,17 @@
 
         function hfApplyStageConfig(data, durationS) {
           var res = (data && data.resolution) || HF_DEFAULT_RESOLUTION;
-          var W = Math.max(1, Math.round(Number(res.width) || HF_DEFAULT_RESOLUTION.width));
-          var H = Math.max(1, Math.round(Number(res.height) || HF_DEFAULT_RESOLUTION.height));
+          // Mirror the published validator's <=8192 bound defensively — the
+          // validator is an optional pre-flight, and an unbounded stage size
+          // would OOM render workers.
+          var W = Math.min(
+            8192,
+            Math.max(1, Math.round(Number(res.width) || HF_DEFAULT_RESOLUTION.width)),
+          );
+          var H = Math.min(
+            8192,
+            Math.max(1, Math.round(Number(res.height) || HF_DEFAULT_RESOLUTION.height)),
+          );
           var root = document.getElementById(HF_ROOT_ID);
           [document.documentElement, document.body, root].forEach(function (el) {
             el.style.width = W + "px";
@@ -532,6 +541,9 @@
         function fitFontSize(text, baseFontSize, fontWeight, fontFamily, maxWidth) {
           var size = baseFontSize;
           var minSize = Math.floor(baseFontSize * 0.45);
+          // minSize is a hard floor returned unverified below — self-heal
+          // accepts residual overflow at the floor (clipped by the stage)
+          // rather than shrinking below legibility.
           while (size > minSize) {
             _fitCtx.font = fontWeight + " " + size + "px " + fontFamily;
             if (_fitCtx.measureText(text).width <= maxWidth) return size;
@@ -605,24 +617,16 @@
         }
 
         function shadowForColor(color) {
-          var hex = color.replace("#", "");
-          var r = parseInt(hex.slice(0, 2), 16);
-          var g = parseInt(hex.slice(2, 4), 16);
-          var b = parseInt(hex.slice(4, 6), 16);
+          // color-mix handles ANY CSS color (hex of either length, rgb()/hsl(),
+          // named colors) — the old hex-pair slicing was why brand colors were
+          // gated behind a strict 6-digit regex, silently dropping payloads the
+          // sibling templates accept.
           return (
-            "0 4px 8px rgba(0,0,0,0.7), 0 0 2px rgba(" +
-            r +
-            "," +
-            g +
-            "," +
-            b +
-            ",1), 0 0 8px rgba(" +
-            r +
-            "," +
-            g +
-            "," +
-            b +
-            ",0.6)"
+            "0 4px 8px rgba(0,0,0,0.7), 0 0 2px " +
+            color +
+            ", 0 0 8px color-mix(in srgb, " +
+            color +
+            " 60%, transparent)"
           );
         }
 
@@ -689,12 +693,14 @@
           stage.style.bottom = Math.round(80 * layout.scaleY) + "px";
 
           var rootEl = document.getElementById(HF_ROOT_ID);
+          // Any non-empty CSS color is honored (mirrors caption-pill-karaoke) —
+          // shadowForColor no longer needs parseable hex, so the old 6-digit
+          // gate (which silently dropped #fff / rgb() / named colors that the
+          // sibling templates accept) is gone.
           var primary = getComputedStyle(rootEl).getPropertyValue("--hf-caption-primary").trim();
           var accent = getComputedStyle(rootEl).getPropertyValue("--hf-caption-accent").trim();
-          hfPrimaryColor = /^#[0-9a-f]{6}$/i.test(primary) ? primary : "#FFFFFF";
-          hfAccentColors = /^#[0-9a-f]{6}$/i.test(accent)
-            ? [accent]
-            : ["#FF76FF", "#FF0002", "#B2F7FF"];
+          hfPrimaryColor = primary || "#FFFFFF";
+          hfAccentColors = accent ? [accent] : ["#FF76FF", "#FF0002", "#B2F7FF"];
 
           var WORDS = normalizeWords(words);
           var GROUPS = makeGroups(WORDS);