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/GifPicker.tsx

@@ -86,7 +86,8 @@ export function GifPicker({ apiKey, onSelect, requestClose }: GifPickerProps) {
         border: '1px solid color-mix(in srgb, var(--lt-accent-orange) 35%, transparent)',
         borderRadius: '4px',
         overflow: 'hidden',
-        boxShadow: '0 4px 24px color-mix(in srgb, var(--lt-accent-orange) 10%, transparent), 0 0 0 1px color-mix(in srgb, var(--lt-accent-orange) 8%, transparent)',
+        boxShadow:
+          '0 4px 24px color-mix(in srgb, var(--lt-accent-orange) 10%, transparent), 0 0 0 1px color-mix(in srgb, var(--lt-accent-orange) 8%, transparent)',
         width: `${PICKER_WIDTH}px`,
       }
     : {

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,
+                }
               : {}),
           }}
         >