Shop: every item is coin-priced; level/rank/achievement only gate the purchase

No more earned-only (rank/wins) cosmetics — every avatar, card back/front,
reaction & sticker pack now has a coin price. Rank/wins/achievement become
purchase requirements (coin · coin+rank · coin+rank+achievement), enforced
client (mock + ShopScreen lock label) and server (ProfileService.ItemGate,
keyed by kind:id). Ownership = default + purchased only.

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

src/lib/i18n.tsx

@@ -312,6 +312,7 @@ const fa: Dict = {
   "shop.includes": "شامل",
   "shop.reqLevel": "سطح",
   "shop.reqRating": "امتیاز",
+  "shop.reqAchv": "دستاورد:",
   "reward.newTitle": "عنوان جدید",
 
   "reactions.title": "شکلک",
@@ -644,6 +645,7 @@ const en: Dict = {
   "shop.includes": "Includes",
   "shop.reqLevel": "Level",
   "shop.reqRating": "Rating",
+  "shop.reqAchv": "Achievement:",
   "reward.newTitle": "New title",
 
   "reactions.title": "Emoji",