feat(overlay): shared layer-stack for topmost-only Escape across modals, popovers, players (R8 S3)

Replace the three mutually-unaware Escape systems — Modal's private modalStack,
the popovers' document listeners with a blanket stopPropagation, and the two
players' modalCount() checks — with one shared lib/layerStack.ts. Every open
dismissable layer registers in open order; a layer acts on Escape only when it
is topmost, and reads anyLayerAbove() to decide whether to defer. Coordination
is now a stack lookup, not event-propagation order, so it no longer depends on
which listener happens to fire first.

- Modal + useDismiss register via the stack; useDismiss drops the blanket
  stopPropagation (its documented side effect: it swallowed a player's own
  Escape while any popover was open).
- Both players register as a layer and defer via anyLayerAbove() instead of
  modalCount(); PlayerModal checks it before its maximise/fullscreen steps.
  A player MENU is a layer too, so it closes first and the next Escape reaches
  the auto-skip-cancel — fixing the documented PlexPlayer bug.
- AnchoredPopover routes non-hover Escape through the stack (floating-ui's own
  escapeKey off there) and registers as a layer, so a player/modal underneath
  defers once S4 migrates the in-player menus. FloatingTree still owns
  popover-vs-popover ordering; the stack adds the cross-type ordering.

frontend/src/components/AnchoredPopover.tsx

@@ -34,6 +34,7 @@ import {
   type Placement,
   type UseRoleProps,
 } from "@floating-ui/react";
+import { useLayer } from "../lib/layerStack";
 
 // R8 popover platform. ONE anchored-popover primitive over @floating-ui/react, replacing the ~9
 // hand-rolled positioning engines (measured flip / width clamp / rAF scroll-follow / scroller-relative
@@ -136,7 +137,11 @@ export function useAnchoredPopover(opts: AnchoredPopoverOptions) {
     handleClose: safePolygon(),
   });
   const focus = useFocus(context, { enabled: isHover });
-  const dismiss = useDismiss(context);
+  // Escape for an interactive (non-hover) popover is dispatched through the shared `layerStack`
+  // (below) so it coordinates with Modals and players, not just other floating nodes — so turn
+  // floating-ui's own Escape off there. Outside-press stays with floating-ui (tree-aware). Hover
+  // tooltips keep floating-ui's Escape and are NOT layers (they mustn't make a player defer).
+  const dismiss = useDismiss(context, { escapeKey: isHover });
   const role = useRole(context, { role: opts.role ?? (isHover ? "tooltip" : "menu") });
   const listNav = useListNavigation(context, {
     enabled: isNav,
@@ -157,6 +162,10 @@ export function useAnchoredPopover(opts: AnchoredPopoverOptions) {
 
   const interactions = useInteractions([click, hover, focus, dismiss, role, listNav, typeahead]);
 
+  // Register the open interactive popover as a dismissable layer (topmost-only Escape, and so a
+  // player/modal underneath defers to it). Hover tooltips are excluded on purpose.
+  useLayer(opts.open && !isHover, () => opts.onOpenChange(false));
+
   return {
     nodeId,
     mode,

frontend/src/components/Modal.tsx

@@ -3,20 +3,12 @@ import { createPortal } from "react-dom";
 import { useTranslation } from "react-i18next";
 import { X } from "lucide-react";
 import { useBackToClose } from "../lib/history";
+import { pushLayer, removeLayer, isTopmost } from "../lib/layerStack";
 
-// Stack of open modals so ESC only closes the topmost one — e.g. an error dialog over the
-// tag editor: pressing ESC dismisses just the error and returns to the editor underneath.
-let modalStack: number[] = [];
-let nextModalId = 1;
-
-/** How many <Modal>s are currently open. The players (which use their own window-level Escape
- * listeners, not this stack) check it so their Escape defers to a Modal opened above them —
- * otherwise one Escape closes the player UNDER the dialog and then the dialog too (U-C). */
-export function modalCount(): number {
-  return modalStack.length;
-}
-
-// Small centered modal shell (portaled to <body>): backdrop + ESC + scroll-lock close.
+// Small centered modal shell (portaled to <body>): backdrop + ESC + scroll-lock close. Each open
+// modal is a layer in the shared `layerStack` so ESC only closes the topmost one — e.g. an error
+// dialog over the tag editor dismisses just the error and returns to the editor underneath, and a
+// player below defers to it (R8 S3).
 export default function Modal({
   title,
   onClose,
@@ -41,10 +33,9 @@ export default function Modal({
   const onCloseRef = useRef(onClose);
   onCloseRef.current = onClose;
   useEffect(() => {
-    const id = nextModalId++;
-    modalStack.push(id);
+    const id = pushLayer();
     const onKey = (e: KeyboardEvent) => {
-      if (e.key === "Escape" && modalStack[modalStack.length - 1] === id) {
+      if (e.key === "Escape" && isTopmost(id)) {
         e.stopPropagation();
         onCloseRef.current();
       }
@@ -54,7 +45,7 @@ export default function Modal({
     document.body.style.overflow = "hidden";
     return () => {
       window.removeEventListener("keydown", onKey);
-      modalStack = modalStack.filter((x) => x !== id);
+      removeLayer(id);
       document.body.style.overflow = prev;
     };
   }, []);

frontend/src/components/PlayerModal.tsx

@@ -27,7 +27,7 @@ import {
 } from "lucide-react";
 import Avatar from "./Avatar";
 import AddToPlaylist from "./AddToPlaylist";
-import { modalCount } from "./Modal";
+import { pushLayer, removeLayer, anyLayerAbove } from "../lib/layerStack";
 import DownloadButton from "./DownloadButton";
 import { api, type Video, type VideoStatus } from "../lib/api";
 import type { YTNamespace, YTPlayer, YTPlayerEvent } from "../lib/youtube";
@@ -490,12 +490,28 @@ export default function PlayerModal({
     staleTime: 5 * 60_000,
   });
 
+  // This player is a dismissable layer: register it so a Modal or popover opened ABOVE it (e.g. the
+  // download dialog, or — after S4 — an anchored menu) takes Escape first and this player defers.
+  const layerIdRef = useRef<number | null>(null);
+  useEffect(() => {
+    const id = pushLayer();
+    layerIdRef.current = id;
+    return () => {
+      removeLayer(id);
+      layerIdRef.current = null;
+    };
+  }, []);
+
   // Keyboard shortcuts (Esc close / F fullscreen / Space play-pause) + background scroll lock.
   // These fire only while focus is on our page, not inside the cross-origin player iframe — so
   // we focus the modal card on open and again on player-ready (autoplay can grab focus).
   useEffect(() => {
     const onKey = (e: KeyboardEvent) => {
       if (e.key === "Escape") {
+        // Defer to any layer opened above the player FIRST (a Modal like the download dialog, or an
+        // anchored popover): it takes the Escape and we do nothing — so we don't also step out of
+        // maximise or close the player underneath it.
+        if (layerIdRef.current != null && anyLayerAbove(layerIdRef.current)) return;
         // In fullscreen, let the browser's Esc exit fullscreen only — don't also close the modal.
         if (fullscreenElement()) return;
         // Same for our own maximise: Esc steps back out of it before it closes the player.
@@ -504,9 +520,6 @@ export default function PlayerModal({
           setMaximized(false);
           return;
         }
-        // Defer to any Modal opened above the player (e.g. the download dialog): its Escape closes
-        // it, ours would otherwise also fire and close the player underneath it (U-C).
-        if (modalCount() > 0) return;
         onClose();
         return;
       }

frontend/src/components/PlexPlayer.tsx

@@ -46,7 +46,7 @@ import { LS, useAccountPersistedObject } from "../lib/storage";
 import { useDismiss } from "../lib/useDismiss";
 import { useScrollFade } from "../lib/useScrollFade";
 import { useBackToClose } from "../lib/history";
-import { modalCount } from "./Modal";
+import { pushLayer, removeLayer, anyLayerAbove } from "../lib/layerStack";
 
 // The rich info overlay (poster/cast/ratings) reuses the same component as the card's info page.
 const PlexInfo = lazy(() => import("./PlexInfo"));
@@ -808,6 +808,18 @@ export default function PlexPlayer({ itemId, onClose, queue }: Props) {
     handleBack();
   }, [handleBack]);
 
+  // This player is a dismissable layer: register it so a Modal or popover opened ABOVE it (its own
+  // settings/tracks menus included) takes Escape first and this player defers (R8 S3).
+  const layerIdRef = useRef<number | null>(null);
+  useEffect(() => {
+    const id = pushLayer();
+    layerIdRef.current = id;
+    return () => {
+      removeLayer(id);
+      layerIdRef.current = null;
+    };
+  }, []);
+
   // --- keyboard --------------------------------------------------------------------------------
   useEffect(() => {
     const onKey = (e: KeyboardEvent) => {
@@ -874,8 +886,10 @@ export default function PlexPlayer({ itemId, onClose, queue }: Props) {
           else handleBack();
           break;
         case "Escape":
-          // Defer to any Modal opened above the player — let its Escape close it, not ours (U-C).
-          if (modalCount() > 0) break;
+          // Defer to any layer opened above the player (Modal or anchored popover) — let it take the
+          // Escape, not us. A player MENU registers as a layer too, so it closes first and the next
+          // Escape reaches the auto-skip-cancel below (the old blanket-stopPropagation bug).
+          if (layerIdRef.current != null && anyLayerAbove(layerIdRef.current)) break;
           if (skipProgressRef.current != null) cancelAutoSkipRef.current();
           else if (menuOpenRef.current) {
             setMenuOpen(false);