feat: show call participants in room list (Discord-style)

apps/web/src/utils/EventPresentationContextProvider.tsx

@@ -0,0 +1,50 @@
+/*
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import React, { type JSX, type PropsWithChildren, useMemo } from "react";
+import { EventPresentationProvider, type EventLayout, type EventPresentation } from "@element-hq/web-shared-components";
+
+import { Layout } from "../settings/enums/Layout";
+import { useSettingValue } from "../hooks/useSettings";
+
+const EVENT_LAYOUT_BY_APP_LAYOUT: Record<Layout, EventLayout> = {
+    [Layout.Bubble]: "bubble",
+    [Layout.Group]: "group",
+    [Layout.IRC]: "irc",
+};
+
+function getEventDensity(layout: Layout, useCompactLayout: boolean): EventPresentation["density"] {
+    return useCompactLayout && layout === Layout.Group ? "compact" : "default";
+}
+
+/** Converts app/web layout settings into shared event presentation settings. */
+export function getEventPresentation(layout: Layout, useCompactLayout: boolean): EventPresentation {
+    return {
+        layout: EVENT_LAYOUT_BY_APP_LAYOUT[layout],
+        density: getEventDensity(layout, useCompactLayout),
+    };
+}
+
+/** Props for the app/web event presentation context provider. */
+export interface EventPresentationContextProviderProps {
+    /** Layout selected by the app/web surface rendering the timeline. */
+    layout: Layout;
+}
+
+/** Provides shared event presentation using app/web-owned layout settings. */
+export function EventPresentationContextProvider({
+    layout,
+    children,
+}: Readonly<PropsWithChildren<EventPresentationContextProviderProps>>): JSX.Element {
+    // Compact density is still owned by app/web; this exposes it as shared event presentation.
+    const useCompactLayout = useSettingValue("useCompactLayout");
+    const eventLayout = EVENT_LAYOUT_BY_APP_LAYOUT[layout];
+    const density = getEventDensity(layout, useCompactLayout);
+    const value = useMemo<EventPresentation>(() => ({ layout: eventLayout, density }), [eventLayout, density]);
+
+    return <EventPresentationProvider value={value}>{children}</EventPresentationProvider>;
+}