Emoji reactions on songs

React to a friend's current song or any of their recent plays: tap an
emoji to add yours (or take it back), "☺+" for the quick six, and a full
picker with search and categories (Unicode emoji up to 13.1, generated
into the shared package so web and mobile match). One reaction per person
per play; a new one replaces the old. Chips show counts and, on hover/
long label, who reacted; yours is highlighted. Listeners and followers get
the update live. Not on your own plays, not across a block (blocking also
clears reactions between the two people).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MzFywujuH9TiuXbr9vjoX8

packages/shared/src/dto.ts

@@ -35,6 +35,13 @@ export interface MeDTO extends UserSummaryDTO {
   entitlements: Entitlements;
 }
 
+/** One emoji on a play, and who left it (newest first). */
+export interface ReactionDTO {
+  emoji: string;
+  count: number;
+  users: UserSummaryDTO[];
+}
+
 export interface NowPlayingDTO {
   user: UserSummaryDTO;
   track: TrackDTO;
@@ -46,6 +53,9 @@ export interface NowPlayingDTO {
   sourceUrl: string | null;
   progressMs: number | null;
   updatedAt: string;
+  /** The play this is, for reactions (null for very old rows). */
+  listenId: string | null;
+  reactions: ReactionDTO[];
 }
 
 /** A feed entry. pinnedAt is set when the viewer pinned this friend. */
@@ -71,9 +81,11 @@ export interface FeaturedSongDTO {
 }
 
 export interface RecentPlayDTO {
+  listenId: string;
   track: TrackDTO;
   source: NowPlayingProvider;
   playedAt: string;
+  reactions: ReactionDTO[];
 }
 
 export interface ProfileDTO {