100 gated gifts (level/rating-locked) + requirement system

Adds ~100 new purchasable gifts that are LOCKED until a level/rating gate is met,
then buyable with coins — value scales with the gate:
- 45 gift avatars (types.ts), 35 gift titles + 20 gift card backs (gamification.ts),
  all reusing existing renderers. Tier (1-5) encoded in the id (-t<n>-).
- Gate model: GIFT_TIERS (shared) → reqLevel/reqRating on AvatarDef/TitleDef/
  CardBackDef + ShopItem. Tiers: t1 free, t2 Lv10, t3 Lv20, t4 Lv35, t5 Rating1700.
- Shop UI: locked cards dim + show the requirement (Lock + "Level 20"), buy
  disabled until met; mock buyItem enforces it offline.
- Server enforces generically — ProfileService parses the tier from the id and
  checks the player's level/rating (no 100-entry mirror). Mirrors GIFT_TIERS.
- i18n shop.reqLevel/reqRating (fa+en).

Verified: tsc + sim + next build + dotnet build all pass.

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

src/lib/online/mock-service.ts

@@ -1031,6 +1031,8 @@ export class MockOnlineService implements OnlineService {
       preview: a.emoji,
       descFa: "آواتار نمایه شما در بازی و جدول",
       descEn: "Your profile avatar in games & leaderboard",
+      reqLevel: a.reqLevel,
+      reqRating: a.reqRating,
     }));
     const backItems: ShopItem[] = CARD_BACKS.filter((c) => c.price > 0).map((c) => ({
       id: c.id,
@@ -1041,6 +1043,8 @@ export class MockOnlineService implements OnlineService {
       preview: c.accent,
       descFa: "طرح پشت کارت‌ها روی میز",
       descEn: "The pattern on the back of your cards",
+      reqLevel: c.reqLevel,
+      reqRating: c.reqRating,
     }));
     const frontItems: ShopItem[] = CARD_FRONTS.filter((c) => c.price > 0).map((c) => ({
       id: c.id,
@@ -1083,6 +1087,8 @@ export class MockOnlineService implements OnlineService {
       preview: "🏷️",
       descFa: "عنوان نمایه که زیر نام شما در بازی و لیست‌ها نشان داده می‌شود",
       descEn: "A profile title shown under your name in games & lists",
+      reqLevel: tt.reqLevel,
+      reqRating: tt.reqRating,
     }));
     const xpItems: ShopItem[] = XP_PACKS.map((x) => ({
       id: x.id,
@@ -1104,6 +1110,10 @@ export class MockOnlineService implements OnlineService {
     const item = items.find((i) => i.id === id);
     if (!item) return { ok: false, messageFa: "آیتم یافت نشد", messageEn: "Item not found" };
 
+    // Purchase gate: locked until the level/rating requirement is met.
+    if ((item.reqLevel && p.level < item.reqLevel) || (item.reqRating && p.rating < item.reqRating))
+      return { ok: false, messageFa: "هنوز باز نشده است", messageEn: "Locked — requirement not met" };
+
     // XP packs are consumable — grant XP instead of adding to an owned list.
     if (item.kind === "xp") {
       if (p.coins < item.price)