fix: ESLint errors and Prettier formatting

ESLint errors:
- usePresenceUpdater: remove redundant `const userId` inside handlePageHide
  that shadowed the outer declaration (no-shadow)
- RoomViewHeader: prefix unused encryptedRoom with _ (no-unused-vars)

Prettier: reformat 14 files to match project style

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/features/settings/general/General.tsx

@@ -509,9 +509,7 @@ function Appearance() {
             <select
               value={fontFamily ?? 'inter'}
               onChange={(e) =>
-                setFontFamily(
-                  e.target.value as 'system' | 'inter' | 'jetbrains-mono' | 'fira-code',
-                )
+                setFontFamily(e.target.value as 'system' | 'inter' | 'jetbrains-mono' | 'fira-code')
               }
               style={{
                 background: 'var(--bg-surface)',
@@ -541,7 +539,14 @@ function Appearance() {
                 type="color"
                 value={mentionHighlightColor || '#4caf50'}
                 onChange={(e) => setMentionHighlightColor(e.target.value)}
-                style={{ width: '36px', height: '28px', cursor: 'pointer', borderRadius: '4px', border: 'none', padding: '2px' }}
+                style={{
+                  width: '36px',
+                  height: '28px',
+                  cursor: 'pointer',
+                  borderRadius: '4px',
+                  border: 'none',
+                  padding: '2px',
+                }}
               />
               {mentionHighlightColor && (
                 <button
@@ -971,7 +976,12 @@ function Editor() {
           after={<Switch variant="Primary" value={editorToolbar} onChange={setEditorToolbar} />}
         />
       </SequenceCard>
-      <SequenceCard className={SequenceCardStyle} variant="SurfaceVariant" direction="Column" gap="300">
+      <SequenceCard
+        className={SequenceCardStyle}
+        variant="SurfaceVariant"
+        direction="Column"
+        gap="300"
+      >
         <SettingTile
           title="Composer Toolbar"
           description="Tap a button to show or hide it in the message composer."