More cosmetics (rank-gated) + steeper level curve capped at 100

Cosmetics — many new variants, the rarer ones gated behind higher ranks:
- Card backs: +midnight/jade/onyx (buy) + crimson/aurora/obsidian/imperial
  (earned by wins/rating up to Master). Card fronts: +sunset/velvet/onyx (buy)
  + goldleaf/crystal/imperial (earned).
- Titles: +marksman, untouchable, sweeper, ruler, platinum_star, diamond_ace,
  immortal, the_one (gated by kots/streak/shutouts/hakem/rating/level/wins),
  mirrored on the server so live games grant them.
- Avatars: list expanded + rank/wins-earned tier (robot/wizard/ninja/king/
  genie/crown) via new ownedAvatarIds(); profile picker shows earned ones,
  shop sells the priced ones.
- Stickers: new Persian-text stamp pack (کوت! / دمت گرم / باریکلا / آخه؟) plus a
  rank-earned Victory pack (بردیم!/حکم) — new inline-SVG art.

Leveling: XP per level now grows (100*l + 15*l²) so each level is harder; higher
leagues grant more XP (×1.5 at 500 stake, ×2 at 1000) so you progress by playing
up. Hard cap at level 100. Mirrored in server Gamification (XpForLevel/MatchXp/
AddXp). Sim now tops out lower (level 20 vs 35 over 500 matches) as intended.

Verified: tsc + next build + dotnet build clean; sim passes; images rebuilt :1500/:1505.

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

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

@@ -38,9 +38,14 @@ public static class Gamification
         return (s.Won ? s.Stake : -s.Stake) + kot;
     }
 
-    public static int XpForLevel(int level) => 100 * level;
-    public static int MatchXp(MatchSummaryDto s) =>
-        40 + (s.Won ? 80 : 0) + s.TricksWon * 5 + (s.KotFor ? 30 : 0);
+    public const int MaxLevel = 100;
+    public static int XpForLevel(int level) => 100 * level + 15 * level * level;
+    private static double LeagueXpFactor(int stake) => stake >= 1000 ? 2.0 : stake >= 500 ? 1.5 : 1.0;
+    public static int MatchXp(MatchSummaryDto s)
+    {
+        int b = 40 + (s.Won ? 80 : 0) + s.TricksWon * 5 + (s.KotFor ? 30 : 0);
+        return (int)Math.Round(b * LeagueXpFactor(s.Stake));
+    }
 
     // metric: wins|kotsFor|bestWinStreak|shutoutWins|games|tricks|level ; ratingFloor>0 = rank ach.
     private record AchDef(string Id, string? Metric, int RatingFloor, int Goal, int Coin, string NameFa, string NameEn, string Icon);
@@ -102,8 +107,12 @@ public static class Gamification
         new("novice", "تازه‌کار", "Novice"), new("winner", "برنده", "Winner"),
         new("expert", "خبره", "Expert"), new("kot_master", "استاد کُت", "Kot Master"),
         new("professional", "حرفه‌ای", "Professional"), new("veteran", "کهنه‌کار", "Veteran"),
-        new("captain", "کاپیتان", "Captain"), new("champion", "قهرمان", "Champion"),
-        new("leader", "فرمانده", "Leader"), new("legend", "اسطوره", "Legend"),
+        new("captain", "کاپیتان", "Captain"), new("marksman", "کماندار", "Marksman"),
+        new("untouchable", "شکست‌ناپذیر", "Untouchable"), new("sweeper", "جاروکش", "Sweeper"),
+        new("ruler", "فرمانروا", "Ruler"), new("champion", "قهرمان", "Champion"),
+        new("platinum_star", "ستاره پلاتین", "Platinum Star"), new("leader", "فرمانده", "Leader"),
+        new("diamond_ace", "آس الماس", "Diamond Ace"), new("immortal", "جاودانه", "Immortal"),
+        new("the_one", "یگانه", "The One"), new("legend", "اسطوره", "Legend"),
     };
 
     private static bool TitleUnlocked(string id, StatsDto st, int rating, int level) => id switch
@@ -115,8 +124,16 @@ public static class Gamification
         "professional" => st.Wins >= 50,
         "veteran" => level >= 30,
         "captain" => st.Wins >= 100,
+        "marksman" => st.KotsFor >= 50,
+        "untouchable" => st.BestWinStreak >= 10,
+        "sweeper" => st.ShutoutWins >= 10,
+        "ruler" => st.HakemRounds >= 50,
         "champion" => rating >= 1300,
+        "platinum_star" => rating >= 1500,
         "leader" => st.Wins >= 250,
+        "diamond_ace" => rating >= 1700,
+        "immortal" => level >= 50,
+        "the_one" => st.Wins >= 500,
         "legend" => rating >= 1900,
         _ => false,
     };
@@ -125,7 +142,8 @@ public static class Gamification
     {
         bool up = false;
         xp += gain;
-        while (xp >= XpForLevel(level)) { xp -= XpForLevel(level); level++; up = true; }
+        while (level < MaxLevel && xp >= XpForLevel(level)) { xp -= XpForLevel(level); level++; up = true; }
+        if (level >= MaxLevel) { level = MaxLevel; xp = Math.Min(xp, XpForLevel(MaxLevel)); }
         return (level, xp, up);
     }