fix(glass): split backdrop-on tier from Plex-art; make app-wide glass near-opaque

Root cause: html[data-backdrop="on"] and .glass-media shared ONE translucent tier, so a value tuned for
Plex art (meant to show its poster through) was forced onto the whole app — over the feed, the nav and
popovers read straight through it. Split them: the app-wide background-image tier is now near-opaque
(surface 88% / card 90% / menu 93% / blur 22px), while the Plex-art tier stays translucent (72/80/85/14).
Tuned live on the user's prod session (50% -> 72% was still too see-through; 88% reads clean). 0.60.2.

VERSION

@@ -1 +1 @@
-0.60.1
+0.60.2

frontend/src/index.css

@@ -97,11 +97,26 @@
    (`html[data-backdrop="on"]`), and on the Plex art-backed detail views (`.glass-media`, which
    have their own art backdrop even when the global image is off). When there's nothing behind the
    glass (image off / perf), the :root defaults keep it solid & readable. ===== */
-html[data-backdrop="on"],
+/* App-wide background image: the glass sits over the FEED (and menus over it), so readability wins.
+   Near-opaque with a strong blur — the backdrop image still tints through as soft colour, but the feed
+   behind the nav/popovers no longer punches through. This is SEPARATE from .glass-media below: the two
+   used to share one tier, which was the root cause — a value tuned for Plex art was forced onto the
+   whole app. (Tuned live on prod, 2026-08-08: 50% → 72% still too see-through; 88% reads clean.) */
+html[data-backdrop="on"] {
+  --glass-blur: 22px;
+  --glass-saturate: 1.6;
+  --glass-dark-bright: 1.2;
+  --glass-surface-alpha: 88%;
+  --glass-card-alpha: 90%;
+  --glass-menu-alpha: 93%;
+  --glass-border-alpha: 80%;
+  --glass-edge: 25%;
+  --glass-inset: 15%;
+  --glass-scrim: 30%;
+}
+/* Plex art-backed detail views: the glass sits over the item's OWN poster/art, which is MEANT to show
+   through richly — keep this tier translucent (unlike the app-wide one above). */
 .glass-media {
-  /* Solidified after user feedback (2026-08-08): 50%/10px let the feed read straight THROUGH the nav
-     and popovers — distractingly transparent. Higher alpha + a stronger blur keep the backdrop image
-     showing through as soft colour without the content behind punching through. */
   --glass-blur: 14px;
   --glass-saturate: 1.6;
   --glass-dark-bright: 1.2;

frontend/src/lib/releaseNotes.ts

@@ -14,6 +14,13 @@ export interface ReleaseEntry {
 }
 
 export const RELEASE_NOTES: ReleaseEntry[] = [
+  {
+    version: "0.60.2",
+    date: "2026-08-08",
+    fixes: [
+      "Follow-up: made the frosted panels solid enough over a background image that the feed no longer shows through the sidebar and menus.",
+    ],
+  },
   {
     version: "0.60.1",
     date: "2026-08-08",