feat: Full UI internationalization, pool hashrate stats, and layout caching

- Replace all hardcoded English strings with TR() translation keys across
  every tab, dialog, and component (~20 UI files)
- Expand all 8 language files (de, es, fr, ja, ko, pt, ru, zh) with
  complete translations (~37k lines added)
- Improve i18n loader with exe-relative path fallback and English base
  fallback for missing keys
- Add pool-side hashrate polling via pool stats API in xmrig_manager
- Introduce Layout::beginFrame() per-frame caching and refresh balance
  layout config only on schema generation change
- Offload daemon output parsing to worker thread
- Add CJK subset fallback font for Chinese/Japanese/Korean glyphs

src/data/exchange_info.cpp

@@ -11,19 +11,10 @@ const std::vector<ExchangeInfo>& getExchangeRegistry()
 {
     static const std::vector<ExchangeInfo> registry = {
         {
-            "TradeOgre",
-            "https://tradeogre.com",
+            "Nonkyc.io",
+            "https://nonkyc.io",
             {
-                {"DRGX", "BTC",  "DRGX/BTC",  "https://tradeogre.com/exchange/DRGX-BTC"},
-                {"DRGX", "LTC",  "DRGX/LTC",  "https://tradeogre.com/exchange/DRGX-LTC"},
-                {"DRGX", "USDT", "DRGX/USDT", "https://tradeogre.com/exchange/DRGX-USDT"},
-            }
-        },
-        {
-            "Exbitron",
-            "https://www.exbitron.com",
-            {
-                {"DRGX", "USDT", "DRGX/USDT", "https://www.exbitron.com/trading/drgxusdt"},
+                {"DRGX", "USDT", "DRGX/USDT", "https://nonkyc.io/market/DRGX_USDT"},
             }
         },
     };

src/data/wallet_state.h

@@ -162,6 +162,9 @@ struct PoolMiningState {
     int64_t memory_used  = 0;
     int     threads_active = 0;
 
+    // Pool-side hashrate (from pool stats API)
+    double pool_hashrate = 0;
+
     // Hashrate history for chart (mirrors MiningInfo::hashrate_history)
     std::vector<double> hashrate_history;
     static constexpr int MAX_HISTORY = 60; // 5 minutes at ~5s intervals