fix(keys): epic-end review round 3 — the part-way clip count shows, busy buttons keep focus, cards say their names

Targeted round over 3cd0c525's fix surfaces: 14 raised, 14 fixed.

- VideoEditor: the "only X of Y clips" toast went silent exactly on the job-cap/quota refusal it was
  written for (req had already reported the error); it now always shows. The cut list holds still while
  Create queues, and a retry continues the "(i/N)" series.
- ChannelPage: Subscribe/Unsubscribe use Button `loading`, "Load more" and ChannelDiscovery's Subscribe
  block the click with aria-disabled instead of native disabled; busy Block/Hide no longer light up on
  hover.
- listNav: an item can name itself (`navItemAttrs(i, name)`) — Plex posters, seasons, episodes, message
  rows and download rows pass their title; focus on a toast's Undo keeps the removed card's slot.
- AnchoredPopover: the hand-back only for focus-managed surfaces (a hover card no longer pulls focus
  back); the dead panel-ref check is gone.
- AccountPanel: no confirmation mail offered to the demo account; send_failed copy no longer blames
  the message for an unreachable server. Pager comment points at scrollParent.

frontend/src/components/ui/AnchoredPopover.tsx

@@ -601,6 +601,11 @@ function PopoverSurfaceInner({
   // in the accessible-name computation — so an explicit ariaLabel is dead unless we drop the ref.
   if (ariaLabel) delete floatingProps["aria-labelledby"];
 
+  // A menu/listbox/dialog traps focus into the surface (and returns it on close). A hover card is
+  // passive, and a COMBOBOX must leave focus in the input (its list is navigated virtually) — neither
+  // is focus-managed.
+  const managed = focusManaged ?? (mode !== "hover" && !isCombobox);
+
   // Where focus goes back on close. floating-ui returns it to the element focused before the open —
   // but when that element is not a Tab stop itself, to its first TABBABLE descendant instead, even
   // when handed the element as a ref (its return runs through `getFirstTabbableElement` either way).
@@ -611,36 +616,35 @@ function PopoverSurfaceInner({
   // panel, and only when the focus was still in a floating layer (or nowhere) as the panel closed:
   // focus the reader moved on to stays where they put it. A menu row's action runs a task later
   // (`closeThenAct`), so a dialog it opens still captures the card as the element to return to.
+  //
+  // Only for a focus-managed surface, whose return this replaces: a hover card or a combobox never
+  // returned focus, and a hover card closing after the reader clicked a link in it must not pull the
+  // focus back to the card under it (deep-review E11 round 3).
   const [returnTo] = useState(() => {
     const active = document.activeElement;
-    return active instanceof HTMLElement && active !== document.body && active.tabIndex < 0
+    return managed &&
+      active instanceof HTMLElement &&
+      active !== document.body &&
+      active.tabIndex < 0
       ? active
       : null;
   });
-  const floatingRef = refs.floating;
   useLayoutEffect(() => {
     if (!returnTo) return;
-    // Read once here: the panel's ref is attached before layout effects run, and cleared by the time
-    // this cleanup does.
-    const floating = floatingRef.current;
     return () => {
+      // "Still in the layer" is read off the portal marker, not the panel: FloatingPortal renders the
+      // panel a commit after this surface mounts, so the panel's ref is still empty when this effect
+      // runs (deep-review E11 round 3).
       const active = document.activeElement;
       const stillOurs =
-        !active ||
-        active === document.body ||
-        !!floating?.contains(active) ||
-        !!active.closest("[data-floating-ui-portal]");
+        !active || active === document.body || !!active.closest("[data-floating-ui-portal]");
       queueMicrotask(() => {
         if (stillOurs && returnTo.isConnected) returnTo.focus({ preventScroll: true });
       });
     };
-  }, [returnTo, floatingRef]);
+  }, [returnTo]);
 
   const zClass = mode === "hover" ? "z-tooltip" : "z-popover";
-  // A menu/listbox/dialog traps focus into the surface (and returns it on close). A hover card is
-  // passive, and a COMBOBOX must leave focus in the input (its list is navigated virtually) — neither
-  // is focus-managed.
-  const managed = focusManaged ?? (mode !== "hover" && !isCombobox);
 
   const surface = (
     <div