Comments on plays

- Anyone who can see a play can read its comments; the player and the people they follow can write.
  The author, the player and admins can delete; comments can be reported (admins see the text).
- Notifications: "commented on" for the player, "replied on" for earlier commenters, each with its
  own setting. Reaction and comment notifications now open the play.
- A 💬 chip with the count next to reactions on the feed and recent plays, opening the thread on
  the app (/play/[id]) and the website. Threads refresh every few seconds while open.
- Blocking removes comments between the two people. Plays with comments survive history trimming.
- Privacy page updated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011Y2iUsKEWDuRGjK5FPmcUP

apps/api/src/services/notifications.ts

@@ -34,6 +34,7 @@ export async function notify(input: {
   listenId?: string | null;
   emoji?: string | null;
   message?: string | null;
+  commentId?: string | null;
 }): Promise<string | null> {
   if (input.userId === input.actorId) return null;
   const n = schema.notifications;
@@ -91,6 +92,7 @@ export async function toNotificationDTOs(rows: Row[]): Promise<NotificationDTO[]
         type: r.type,
         actor,
         track: r.trackId ? (tracks.get(r.trackId) ?? null) : null,
+        listenId: r.listenId,
         emoji: r.emoji,
         message: r.message,
         read: Boolean(r.readAt),