Fix simplified layout applying to other pages in web UI (#39570)

app/javascript/mastodon/features/ui/index.jsx

@@ -185,7 +185,7 @@ class SwitchingColumnsArea extends PureComponent {
 
     return (
       <ColumnsContextProvider multiColumn={!singleColumn}>
-        <ColumnsArea ref={this.setRef} singleColumn={singleColumn} domain={domain} minimalShell={!signedIn && landingPage === 'overview'}>
+        <ColumnsArea ref={this.setRef} singleColumn={singleColumn} domain={domain} minimalShell={!signedIn && landingPage === 'overview' && pathName.startsWith('/overview')}>
           <WrappedSwitch>
             <Redirect from='/' to={{pathname: rootRedirect, state: {...this.props.location.state, focusTarget: false}}} exact />