fix(release): draw the corpus audit card opaque and gate on it

The first recording of the card was legible but translucent, so the bottom nav
and the journal's body copy ghosted through its empty lower rows. The card is
now fully opaque and the on-screen proof rejects a background with any alpha, so
a future edit cannot reintroduce the bleed unnoticed.

scripts/record_release_demo.mjs

@@ -653,7 +653,7 @@ const panelOk = await page.evaluate(rows => {
   panel.id = 'corpus-audit';
   Object.assign(panel.style, {
     position: 'fixed', inset: '96px 14px 40px 14px', zIndex: '15000',
-    background: 'rgba(24,20,18,.97)', color: '#f6f1e6', borderRadius: '18px',
+    background: '#181412', color: '#f6f1e6', borderRadius: '18px',
     border: '1px solid rgba(245,201,91,.45)', padding: '13px 13px 11px',
     font: '600 10.5px/1.5 ui-monospace, SFMono-Regular, Menlo, monospace',
     display: 'flex', flexDirection: 'column', gap: '1px', overflow: 'hidden',
@@ -689,11 +689,16 @@ const panelProof = await page.evaluate(() => {
   if (!panel) return { ok: false, reason: 'panel missing' };
   const rect = panel.getBoundingClientRect();
   const topmost = document.elementFromPoint(Math.round(rect.left + rect.width / 2), Math.round(rect.top + rect.height / 2));
+  const background = getComputedStyle(panel).backgroundColor;
+  // A translucent card lets the nav bar and body copy ghost through its empty rows, which reads as a
+  // sloppy overlay on the thinnest part of the frame. The card must be fully opaque.
+  const opaque = !/^rgba\(.*,\s*(0?\.\d+|0)\)$/.test(background);
   return {
-    ok: rect.top >= 60 && rect.bottom <= window.innerHeight && rect.width > 300 && rect.height > 300
+    ok: opaque && rect.top >= 60 && rect.bottom <= window.innerHeight && rect.width > 300 && rect.height > 300
       && (topmost === panel || panel.contains(topmost)) && panel.scrollHeight <= panel.clientHeight + 1,
     top: Math.round(rect.top), height: Math.round(rect.height), width: Math.round(rect.width),
-    scroll: panel.scrollHeight, client: panel.clientHeight, covered: topmost === panel || panel.contains(topmost),
+    scroll: panel.scrollHeight, client: panel.clientHeight, background, opaque,
+    covered: topmost === panel || panel.contains(topmost),
   };
 });
 if (!panelProof.ok) throw new Error(`Corpus audit card is not fully readable on screen: ${JSON.stringify(panelProof)}`);