Add bot-driven room app UI via im.paarrot.ui state.

Bots can publish a declarative panel UI that takes over a room; user
actions are sent as im.paarrot.ui.action timeline events.

src/app/features/room/Room.tsx

@@ -1,5 +1,5 @@
-import React, { useCallback, useEffect } from 'react';
-import { Box, Line } from 'folds';
+import React, { useCallback, useEffect, useMemo, useState } from 'react';
+import { Box, Button, Line, Text, config } from 'folds';
 import { decodeRouteParam } from '../../pages/pathUtils';
 import { useParams } from 'react-router-dom';
 import { isKeyHotkey } from 'is-hotkey';
@@ -18,8 +18,11 @@ import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { useRoomMembers } from '../../hooks/useRoomMembers';
 import { activeRoomIdAtom } from '../../state/activeRoom';
 import { isMediaDrawerAtom } from '../../state/mediaDrawer';
-import { isForum } from '../../utils/room';
+import { isForum, parsePaarrotUiContent } from '../../utils/room';
 import { ForumRoomView } from './ForumRoomView';
+import { useStateEvent } from '../../hooks/useStateEvent';
+import { StateEvent } from '../../../types/matrix/room';
+import { RoomAppView } from '../room-app';
 
 export function Room() {
   const { eventId: rawEventId } = useParams();
@@ -41,6 +44,16 @@ export function Room() {
   const showRightDrawer =
     !skinny && (isPeopleDrawer || isMediaDrawer);
 
+  const uiEvent = useStateEvent(room, StateEvent.PaarrotUi);
+  const hasAppUi = useMemo(() => !!parsePaarrotUiContent(uiEvent?.getContent()), [uiEvent]);
+  const [preferChat, setPreferChat] = useState(false);
+
+  useEffect(() => {
+    setPreferChat(false);
+  }, [room.roomId]);
+
+  const showAppView = !forumRoom && hasAppUi && !preferChat;
+
   // Update titlebar with current room ID
   useEffect(() => {
     setActiveRoomId(room.roomId);
@@ -63,10 +76,38 @@ export function Room() {
     <PowerLevelsContextProvider value={powerLevels}>
       <Box grow="Yes">
         {!showMediaSolo &&
-          (forumRoom ? (
+          (showAppView ? (
+            <RoomAppView room={room} onShowChat={() => setPreferChat(true)} />
+          ) : forumRoom ? (
             <ForumRoomView room={room} eventId={eventId} />
           ) : (
-            <RoomView room={room} eventId={eventId} />
+            <Box grow="Yes" direction="Column" style={{ minWidth: 0, minHeight: 0 }}>
+              {hasAppUi && preferChat && (
+                <Box
+                  shrink="No"
+                  alignItems="Center"
+                  justifyContent="SpaceBetween"
+                  gap="200"
+                  style={{
+                    padding: `${config.space.S200} ${config.space.S300}`,
+                    borderBottom: '1px solid var(--bq-surface-border, CurrentColor)',
+                  }}
+                >
+                  <Text size="T300">Room app available</Text>
+                  <Button
+                    size="300"
+                    variant="Primary"
+                    radii="300"
+                    onClick={() => setPreferChat(false)}
+                  >
+                    <Text size="B300">Show app</Text>
+                  </Button>
+                </Box>
+              )}
+              <Box grow="Yes" direction="Column" style={{ minWidth: 0, minHeight: 0 }}>
+                <RoomView room={room} eventId={eventId} />
+              </Box>
+            </Box>
           ))}
         {showMediaSolo && <MediaDrawer room={room} solo />}
         {!showMediaSolo && showRightDrawer && (