feat(avatars): show the uploaded profile photo everywhere

Previously the uploaded profile photo only appeared in a few places (profile,
top bar, leaderboard, public profile); chat, friends, game table, match intro,
post-match roster and private rooms showed the emoji avatar only.

- carry avatarImage end-to-end:
  - server DTOs: FriendDto, SeatPlayerDto, RoomPlayerDto, MatchmakeRequest +
    Player/SeatSlot/PSeat; ResolveProfile now returns avatarImage; FriendDtoFor
    fills it from the profile.
  - client types: Friend, RoomSeat.player, MatchmakingState.players,
    ServerSeatPlayer, SeatPlayer (adds avatarId + avatarImage).
  - signalr-service: send my avatarImage on StartMatchmaking/CreatePrivateRoom;
    carry it through mapRoom.
  - game-store: applyServerState + newOnlineMatch + offline match now populate
    avatarId/avatarImage (seat 0 uses your own profile photo).
- render every avatar through the shared <Avatar> component (image → emoji
  fallback): ChatScreen, FriendsScreen (requests/friends/chats), GameTable
  seats, MatchIntroOverlay, MatchPlayersList, RoomScreen.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/lib/online/signalr-service.ts

@@ -45,7 +45,7 @@ interface ServerRoom {
   targetScore: number;
   stake: number;
   ranked: boolean;
-  seats: { seat: number; kind: string; player?: { id: string; displayName: string; avatar: string; level: number } }[];
+  seats: { seat: number; kind: string; player?: { id: string; displayName: string; avatar: string; avatarImage?: string; level: number } }[];
 }
 
 const EMPTY_ROOM: Room = {
@@ -318,7 +318,7 @@ export class SignalrService implements OnlineService {
     const p = this.cachedProfile ?? (await this.getProfile().catch(() => this.mock.getProfile()));
     this.emitMM("searching");
     await this.conn?.invoke("StartMatchmaking", {
-      name: p.displayName, avatar: p.avatar, level: p.level, plan: p.plan,
+      name: p.displayName, avatar: p.avatar, level: p.level, plan: p.plan, avatarImage: p.avatarImage,
     });
   }
 
@@ -497,7 +497,7 @@ export class SignalrService implements OnlineService {
     await this.connect();
     const p = this.cachedProfile ?? (await this.getProfile().catch(() => this.mock.getProfile()));
     await this.conn?.invoke("CreatePrivateRoom",
-      { name: p.displayName, avatar: p.avatar, level: p.level, plan: p.plan }, o.stake, o.targetScore);
+      { name: p.displayName, avatar: p.avatar, level: p.level, plan: p.plan, avatarImage: p.avatarImage }, o.stake, o.targetScore);
     return this.waitRoom();
   }
   async setPartner(_roomId: string, friendId: string | null) {