Leaderboard avatar+level+XP bar; mobile table overlap fixes

Leaderboard: each row now shows the player avatar (photo or emoji) with a level
badge ring and a progress-to-next-level bar (LeaderboardEntry gained
levelProgress + avatarImage; mock fills real XP for you, random for others).

Mobile table: the played-card pile now scales inward on narrow screens so it no
longer overlaps the opponents' side stacks (trickScale by viewport); seat
avatars render above the stacks (z-20) so the side player isn't hidden; side
hands nudged to the edges + top hand raised slightly on phones.

Verified: tsc + next build clean; web image rebuilt on :1500.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/lib/online/mock-service.ts

@@ -9,6 +9,7 @@ import {
   STICKER_PACKS,
   applyMatchResult,
   dailyRewardFor,
+  xpNeededForLevel,
 } from "./gamification";
 import {
   CreateRoomOptions,
@@ -820,14 +821,17 @@ export class MockOnlineService implements OnlineService {
       avatar: pick(AVATARS).id,
       level: randInt(5, 60),
       rating: randInt(1000, 2200),
+      levelProgress: Math.random(),
       isYou: false,
     }));
     const you = {
       id: p.id,
       displayName: p.displayName,
       avatar: p.avatar,
+      avatarImage: p.avatarImage,
       level: p.level,
       rating: p.rating,
+      levelProgress: Math.min(1, p.xp / xpNeededForLevel(p.level)),
       isYou: true,
     };
     const all = [...others, you].sort((a, b) => b.rating - a.rating);