fix: remaining LOTUS_BUGS.md items — hardcoded hex and a11y

- GifPicker: replace #FF6B00 and #060c14 with var(--lt-accent-orange) and
  var(--lt-bg-secondary); rgba opacity values use color-mix()
- VoiceMessageRecorder: replace #FF6B00 and #00FF88 waveform/dot colors
  with var(--lt-accent-orange) / var(--lt-accent-green)
- Presence: replace aria-labelledby referencing a lazy tooltip ID with a
  direct aria-label so screen readers always have the text in the DOM

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

src/app/components/GifPicker.tsx

@@ -36,12 +36,12 @@ function GifPickerInner({ onSelect, requestClose, lotusTerminal }: GifPickerInne
         <div
           style={{
             padding: '5px 10px 4px',
-            borderBottom: '1px solid rgba(255,107,0,0.2)',
+            borderBottom: '1px solid color-mix(in srgb, var(--lt-accent-orange) 20%, transparent)',
             fontFamily: "'JetBrains Mono', 'Cascadia Code', monospace",
             fontSize: '10px',
             fontWeight: 700,
             letterSpacing: '0.1em',
-            color: '#FF6B00',
+            color: 'var(--lt-accent-orange)',
             userSelect: 'none',
           }}
         >
@@ -82,11 +82,11 @@ export function GifPicker({ apiKey, onSelect, requestClose }: GifPickerProps) {
 
   const containerStyle = lotusTerminal
     ? {
-        background: '#060c14',
-        border: '1px solid rgba(255,107,0,0.35)',
+        background: 'var(--lt-bg-secondary)',
+        border: '1px solid color-mix(in srgb, var(--lt-accent-orange) 35%, transparent)',
         borderRadius: '4px',
         overflow: 'hidden',
-        boxShadow: '0 4px 24px rgba(255,107,0,0.10), 0 0 0 1px rgba(255,107,0,0.08)',
+        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`,
       }
     : {