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/components/VoiceMessageRecorder.tsx

@@ -214,7 +214,11 @@ export function VoiceMessageRecorder({ onSend, onError }: VoiceRecorderProps) {
             minWidth: toRem(32),
             fontVariantNumeric: 'tabular-nums',
             ...(lotusTerminal
-              ? { fontFamily: 'JetBrains Mono, monospace', color: 'var(--lt-accent-green)', fontWeight: 700 }
+              ? {
+                  fontFamily: 'JetBrains Mono, monospace',
+                  color: 'var(--lt-accent-green)',
+                  fontWeight: 700,
+                }
               : {}),
           }}
         >