feat: reaction TDS styling, debounce read receipts, Escape to skip boot, type fixes

- lotus-terminal.css.ts: add reaction chip styles for dark + light TDS modes
  (cyan border/bg for unselected, orange accent for own/pressed reactions)
- useRoomReadPositions: debounce receipt handler at 150ms (M-3)
- lotus-boot.ts: Escape key skips boot animation (I-3)
- RoomInput.tsx: replace (uploadRes as any) with typed assertion (M-7)
- CallEmbedProvider: call mention detection, audio cleanup, display name (C-1, C-2, M-5)
- EventReaders: timestamps in seen-by modal, filter self, TDS styling
- ReadReceiptAvatars: StackedAvatar pill, TDS visual treatment
- chatBackground: add waves/neon/aurora backgrounds
- RoomView: auto-apply tactical bg when TDS active and bg is none
- settings: extend ChatBackground union type

src/app/features/room/RoomView.tsx

@@ -62,6 +62,7 @@ export function RoomView({ eventId }: { eventId?: string }) {
   const roomInputRef = useRef<HTMLDivElement>(null);
   const roomViewRef = useRef<HTMLDivElement>(null);
   const [chatBackground] = useSetting(settingsAtom, 'chatBackground');
+  const [lotusTerminal] = useSetting(settingsAtom, 'lotusTerminal');
   const theme = useTheme();
   const isDark = theme.kind === ThemeKind.Dark;
 
@@ -98,7 +99,7 @@ export function RoomView({ eventId }: { eventId?: string }) {
   );
 
   return (
-    <Page ref={roomViewRef} style={getChatBg(chatBackground, isDark)}>
+    <Page ref={roomViewRef} style={getChatBg(lotusTerminal && chatBackground === 'none' ? 'tactical' : chatBackground, isDark)}>
       <Box grow="Yes" direction="Column">
         <RoomTimeline
           key={roomId}