feat: Phase 3 Aether Drift — voice & video component token migration

Migrate all 10 voice/video components from Discord visual language to
Aether Drift design system. Zero discord-* classes or hardcoded hex
values remain in components/voice/.

Key changes:
- Status indicators use pastel accents: mint (connected/speaking),
  amber (connecting/idle), rose (muted/deafened/error)
- VoiceControlBar converted to frosted glass-bubble material
- ConnectionInfoPopover and ScreenShareSettingsPopover use glass popovers
- Speaking ring glow changed from Discord green to mint (#86efac)
- Slider accents use lavender instead of blurple
- All bg/text/border tokens mapped to surface-*/txt-*/interactive-* system

packages/web/src/components/voice/VoiceChatPanel.tsx

@@ -13,13 +13,13 @@ export function VoiceChatPanel({ channelId, channelName }: VoiceChatPanelProps)
   const toggleVoiceChat = useUIStore((s) => s.toggleVoiceChat);
 
   return (
-    <div className="w-[340px] flex-shrink-0 bg-discord-bg-primary flex flex-col border-l border-[#2b2d31]">
+    <div className="w-[340px] flex-shrink-0 bg-surface-chat flex flex-col border-l border-border-soft">
       {/* Chat header */}
       <div className="h-12 px-4 flex items-center justify-between shadow-header flex-shrink-0">
-        <span className="font-bold text-discord-text-primary text-[16px]">Chat</span>
+        <span className="font-bold text-txt-primary text-[16px]">Chat</span>
         <button
           onClick={toggleVoiceChat}
-          className="w-7 h-7 flex items-center justify-center text-discord-text-muted hover:text-discord-text-primary transition-colors rounded"
+          className="w-7 h-7 flex items-center justify-center text-txt-tertiary hover:text-txt-primary transition-colors rounded"
           title="Close Chat"
         >
           <svg width="18" height="18" viewBox="0 0 24 24" fill="currentColor">