feat: Integrate forum layout support across various components and enhance room handling logic

src/app/features/forum/ForumAwareSpaceLayout.tsx

@@ -0,0 +1,53 @@
+import React, { CSSProperties } from 'react';
+import { Outlet } from 'react-router-dom';
+import { Box } from 'folds';
+import classNames from 'classnames';
+import { useSpace } from '../../hooks/useSpace';
+import { PageRoot } from '../../components/page';
+import { AnimatedOutlet } from '../../components/AnimatedOutlet';
+import { MobileFriendlyPageNav } from '../../pages/MobileFriendly';
+import { SPACE_PATH } from '../../pages/paths';
+import { Space } from '../../pages/client/space/Space';
+import { shouldShowForumLobby } from '../../utils/room';
+import { ContainerColor } from '../../styles/ContainerColor.css';
+import * as theme from './forumTheme.css';
+
+const forumOutletShell: CSSProperties = {
+  display: 'flex',
+  flex: 1,
+  flexDirection: 'column',
+  minHeight: 0,
+  minWidth: 0,
+  overflow: 'hidden',
+};
+
+/**
+ * Forum: server list only — forum fills main pane.
+ * Other spaces: space sidebar + outlet.
+ */
+export function ForumAwareSpaceLayout() {
+  const space = useSpace();
+  const isForum = shouldShowForumLobby(space);
+
+  if (isForum) {
+    return (
+      <Box grow="Yes" className={classNames(ContainerColor({ variant: 'Background' }), theme.ForumAppRoot)}>
+        <div style={forumOutletShell}>
+          <Outlet />
+        </div>
+      </Box>
+    );
+  }
+
+  return (
+    <PageRoot
+      nav={
+        <MobileFriendlyPageNav path={SPACE_PATH}>
+          <Space />
+        </MobileFriendlyPageNav>
+      }
+    >
+      <AnimatedOutlet />
+    </PageRoot>
+  );
+}