Achievements overhaul: 37 achievements, page with tabs, leagues, gating

Achievements (client + server mirror, metric-driven so the list is one source):
- 37 achievements across 6 categories (Victories, Kot, Streaks, Levels, Ranks,
  Veterancy) incl. 7–0 sweeps, kot milestones (1/5/10/25/50/100), win streaks
  (3/5/10/15), level milestones every 5 (5..50), rank floors, games/tricks.
- New AchievementsScreen with category tabs, progress bars, coin + sticker-unlock
  badges, and unlocked/locked states; summary header (unlocked count + coins).
- Some achievements unlock sticker packs: Seven–Zip→Hokm, 25 Kots→Taunts,
  100 Wins→Persian (ownedStickerPackIds now also honors profile.unlocked).
- Prestige titles added: Expert, Professional, Captain, Leader (+ existing).
- Tracks new stat shutoutWins; MatchSummary.shutout (7–0). Profile shows a
  6-item preview + "view all" link.

Leagues: 3 ranked entry tiers — Starter (100, lvl1), Pro (500, lvl10),
Expert (1000, lvl20). Higher league stakes more, so wins/losses swing bigger;
kot bonus now scales to the stake (40%). OnlineLobby shows league cards with
level gating.

Profile photo upload gated to level 25 (client button + server Update guard).

Win animation: PostMatchRewardsModal now shows an animated coins-won count-up
hero on a win.

Verified: dotnet build + tsc + next build clean; sim unlocks 26 achievements
over 500 matches; live server grants first_win/first_kot/shutout_1 and pays
2050 coins on an expert-league shutout+kot win. Images rebuilt on :1500/:1505.

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

server/src/Hokm.Server/Profiles/ProfileService.cs

@@ -59,7 +59,8 @@ public class ProfileService
         var p = await GetOrCreate(uid, null);
         if (patch.TryGetProperty("displayName", out var dn) && dn.ValueKind == JsonValueKind.String) p.DisplayName = dn.GetString()!;
         if (patch.TryGetProperty("avatar", out var av) && av.ValueKind == JsonValueKind.String) p.Avatar = av.GetString()!;
-        if (patch.TryGetProperty("avatarImage", out var ai) && ai.ValueKind == JsonValueKind.String) p.AvatarImage = ai.GetString();
+        // Custom photo upload is gated behind level 25.
+        if (p.Level >= 25 && patch.TryGetProperty("avatarImage", out var ai) && ai.ValueKind == JsonValueKind.String) p.AvatarImage = ai.GetString();
         if (patch.TryGetProperty("title", out var ti) && ti.ValueKind == JsonValueKind.String) p.Title = ti.GetString();
         if (patch.TryGetProperty("cardFront", out var cf) && cf.ValueKind == JsonValueKind.String) p.CardFront = cf.GetString()!;
         if (patch.TryGetProperty("cardBack", out var cb) && cb.ValueKind == JsonValueKind.String) p.CardBack = cb.GetString()!;