Store XP packs (expensive), winner 2x XP, premium perks

- XP packs in the store (coin-priced, intentionally expensive): xp1 200/5k,
  xp2 600/12k, xp3 1500/25k. Consumable (grant XP, can level up) — server
  ShopBuy handles kind "xp" via an authoritative XpPacks map + Gamification.GrantXp;
  mock mirrors. New shop section + shop.xp/xpHint i18n.
- Every game grants XP and the WINNER earns 2x: matchXp is now
  base*(won?2:1)*leagueFactor (was a flat +80 win bonus). Mirrored server-side.
- Premium (pro) perks: 1.5x XP multiplier (applied in applyMatchResult /
  ApplyMatch by plan), plus animated shimmering gold chat bubbles for your own
  messages (premium-chat CSS; ChatScreen gates on plan).

Verified: tsc + next + dotnet build clean; sim passes; live server — buying xp2
took L1→L3 and deducted 12k coins under the new curve. Images rebuilt :1500/:1505.

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

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

@@ -41,10 +41,12 @@ public static class Gamification
     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 const double PremiumXpMult = 1.5;
     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));
+        // Every game grants XP; the winner earns double.
+        int b = 40 + s.TricksWon * 5 + (s.KotFor ? 30 : 0);
+        return (int)Math.Round(b * (s.Won ? 2 : 1) * LeagueXpFactor(s.Stake));
     }
 
     // metric: wins|kotsFor|bestWinStreak|shutoutWins|games|tricks|level ; ratingFloor>0 = rank ach.
@@ -138,6 +140,14 @@ public static class Gamification
         _ => false,
     };
 
+    /// <summary>Grant raw XP to a profile (store XP packs); mutates level/xp, capped at 100.</summary>
+    public static void GrantXp(ProfileDto p, int xp)
+    {
+        var r = AddXp(p.Level, p.Xp, xp);
+        p.Level = r.level;
+        p.Xp = r.xp;
+    }
+
     private static (int level, int xp, bool up) AddXp(int level, int xp, int gain)
     {
         bool up = false;
@@ -154,7 +164,9 @@ public static class Gamification
         int rDelta = RatingDelta(s, p.Rating, oppRating);
         int ratingAfter = Math.Max(0, ratingBefore + rDelta);
         int cDelta = CoinDelta(s);
-        var lvl = AddXp(p.Level, p.Xp, MatchXp(s));
+        // Premium (pro) players earn a multiple of XP.
+        int xpGain = (int)Math.Round(MatchXp(s) * (p.Plan == "pro" ? PremiumXpMult : 1.0));
+        var lvl = AddXp(p.Level, p.Xp, xpGain);
 
         var st = p.Stats;
         int cur = s.Won ? st.CurrentWinStreak + 1 : 0;
@@ -209,7 +221,7 @@ public static class Gamification
             CoinsBefore = coinsBefore,
             CoinsAfter = coinsAfter,
             CoinsDelta = coinsAfter - coinsBefore,
-            XpGained = MatchXp(s),
+            XpGained = xpGain,
             LevelBefore = levelBefore,
             LevelAfter = lvl.level,
             LeveledUp = lvl.level > levelBefore,

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

@@ -112,9 +112,30 @@ public class ProfileService
 
     /* ----------------------------- shop ------------------------------- */
 
+    // Coin-priced XP packs (XP is intentionally expensive). Server-authoritative.
+    public static readonly Dictionary<string, (int Price, int Xp)> XpPacks = new()
+    {
+        ["xp1"] = (5000, 200),
+        ["xp2"] = (12000, 600),
+        ["xp3"] = (25000, 1500),
+    };
+
     public async Task<(bool ok, ProfileDto? profile, string error)> ShopBuy(string uid, string kind, string id, int price)
     {
         var p = await GetOrCreate(uid, null);
+
+        // XP packs are consumable (grant XP, may level up) — not added to an owned list.
+        if (kind == "xp")
+        {
+            if (!XpPacks.TryGetValue(id, out var pk)) return (false, p, "bad_kind");
+            if (p.Coins < pk.Price) return (false, p, "insufficient");
+            p.Coins -= pk.Price;
+            Gamification.GrantXp(p, pk.Xp);
+            await Save(p);
+            await Ledger(uid, "xp", -pk.Price, id);
+            return (true, p, "");
+        }
+
         var list = kind switch
         {
             "avatar" => p.OwnedAvatars,