UX: landscape result screen, chat emojis, unread badges, remove XP text

- PostMatchRewardsModal: short-height (landscape) compaction so the win/forfeit
  result fits without overflow (smaller emoji/coins/padding, max-h 94dvh, wider).
- Chat: emoji/sticker picker (owned reactions) — tap to send; hidden on focus.
- Unread messages: online-store now tracks a total `unread` (from
  listConversations); NavRail Friends icon shows a badge (unread + requests),
  refreshed every 12s on every screen; Friends «پیام‌ها» tab badged too.
  (Per-conversation unread badges already existed.)
- Remove "XP گران است" / "XP is expensive" from shop.xpHint.

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

src/lib/i18n.tsx

@@ -151,6 +151,7 @@ const fa: Dict = {
   "chat.title": "گفتگو",
   "chat.placeholder": "پیام بنویسید…",
   "chat.send": "ارسال",
+  "chat.emoji": "ایموجی",
   "chat.empty": "گفتگو را شروع کنید",
   "friends.message": "پیام",
 
@@ -315,7 +316,7 @@ const fa: Dict = {
   "shop.titles": "عناوین",
   "shop.titlesHint": "عنوان شما زیر نامتان در بازی و لیست‌ها نمایش داده می‌شود",
   "shop.xp": "امتیاز تجربه (XP)",
-  "shop.xpHint": "افزایش سریع سطح — XP گران است",
+  "shop.xpHint": "افزایش سریع سطح",
   "shop.includes": "شامل",
   "shop.reqLevel": "سطح",
   "shop.reqRating": "امتیاز",
@@ -501,6 +502,7 @@ const en: Dict = {
   "chat.title": "Chat",
   "chat.placeholder": "Type a message…",
   "chat.send": "Send",
+  "chat.emoji": "Emoji",
   "chat.empty": "Start the conversation",
   "friends.message": "Message",
 
@@ -662,7 +664,7 @@ const en: Dict = {
   "shop.titles": "Titles",
   "shop.titlesHint": "Your title shows under your name in games & lists",
   "shop.xp": "XP packs",
-  "shop.xpHint": "Level up faster — XP is expensive",
+  "shop.xpHint": "Level up faster",
   "shop.includes": "Includes",
   "shop.reqLevel": "Level",
   "shop.reqRating": "Rating",