Add MSC4522 username colors, release notes dialog, and profile layout fixes.

Replace legacy profile style metadata with MSC4133 profile fields, add in-app update notes, tighten account profile name spacing, and wire desktop media save helpers through the client.

src/app/features/settings/about/About.tsx

@@ -1,5 +1,7 @@
 import React, { useCallback, useEffect, useState } from 'react';
-import { getVersion } from '@tauri-apps/api/app';
+import { getAppVersion } from '../../../utils/appVersion';
+import { useOpenReleaseNotesDialog } from '../../../components/updates-dialog/UpdatesDialogHost';
+import { getCurrentUpdatePreview } from '../../../data/updateNotes';
 import { Box, Text, IconButton, Scroll, Button, config, toRem } from 'folds';
 import { Icon, Icons } from '../../../components/icons';
 import { Page, PageContent, PageHeader } from '../../../components/page';
@@ -15,6 +17,7 @@ type AboutProps = {
 };
 export function About({ requestClose }: AboutProps) {
   const mx = useMatrixClient();
+  const openReleaseNotes = useOpenReleaseNotesDialog();
   const [version, setVersion] = useState<string>('');
   const [protocolStatus, setProtocolStatus] = useState<string>('Checking desktop protocol integration...');
   const [protocolBusy, setProtocolBusy] = useState<boolean>(false);
@@ -93,10 +96,13 @@ export function About({ requestClose }: AboutProps) {
   };
 
   useEffect(() => {
-    getVersion().then(setVersion).catch(() => setVersion('unknown'));
+    getAppVersion().then(setVersion).catch(() => setVersion('unknown'));
     refreshProtocolStatus();
+    getCurrentUpdatePreview().then(setUpdatePreview).catch(() => setUpdatePreview(null));
   }, [refreshProtocolStatus]);
 
+  const [updatePreview, setUpdatePreview] = useState<{ title: string; description: string } | null>(null);
+
   return (
     <Page>
       <PageHeader outlined={false}>
@@ -151,6 +157,36 @@ export function About({ requestClose }: AboutProps) {
                   </Box>
                 </Box>
               </Box>
+              <Box direction="Column" gap="100">
+                <Text size="L400">What&apos;s new</Text>
+                <SequenceCard
+                  className={SequenceCardStyle}
+                  variant="SurfaceVariant"
+                  direction="Column"
+                  gap="300"
+                >
+                  <SettingTile
+                    title={updatePreview?.title ?? 'Release notes'}
+                    description={
+                      updatePreview
+                        ? `Paarrot ${version} — ${updatePreview.description}`
+                        : 'View highlights from the latest Paarrot update.'
+                    }
+                    after={
+                      <Button
+                        onClick={openReleaseNotes}
+                        variant="Secondary"
+                        fill="Soft"
+                        size="300"
+                        radii="300"
+                        outlined
+                      >
+                        <Text size="B300">View updates</Text>
+                      </Button>
+                    }
+                  />
+                </SequenceCard>
+              </Box>
               <Box direction="Column" gap="100">
                 <Text size="L400">Options</Text>
                 <SequenceCard