style(glass): tune the over-image tier — cards let the image show through

The app-wide 'glass over image' tier: panels stay near-opaque (surface 90%, menu 100%)
so chrome text is readable, but glass-card drops to 50% so the per-scheme backdrop image
gently shows through the feed cards (blur 22, inset 10). User-tuned via the live GlassTuner
and validated ("the image just barely shows through, text still readable"); supersedes the
uniform-88% pass that had killed the image-through-cards look. Only the data-backdrop=on
tier — :root (image off) and .glass-media (Plex art) unchanged.

frontend/src/lib/releaseNotes.ts

@@ -14,6 +14,13 @@ export interface ReleaseEntry {
 }
 
 export const RELEASE_NOTES: ReleaseEntry[] = [
+  {
+    version: "0.60.7",
+    date: "2026-08-09",
+    fixes: [
+      "Refined the frosted-glass look when a background image is on: the feed cards now let the image gently show through, while the panels and menus stay solid so text everywhere stays readable.",
+    ],
+  },
   {
     version: "0.60.6",
     date: "2026-08-09",