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/ui/material/typography.cpp

@@ -246,11 +246,14 @@ ImFont* Typography::loadFont(ImGuiIO& io, int weight, float size, const char* na
     cfg.PixelSnapH = true;
     
     // Include default ASCII + Latin, Latin Extended (for Spanish/multilingual),
-    // plus arrows (⇄ U+21C4), math (≈ U+2248),
-    // general punctuation (— U+2014, … U+2026, etc.)
+    // Cyrillic (for Russian), Greek, plus arrows (⇄ U+21C4),
+    // math (≈ U+2248), general punctuation (— U+2014, … U+2026, etc.)
     static const ImWchar glyphRanges[] = {
         0x0020, 0x00FF,  // Basic Latin + Latin-1 Supplement
         0x0100, 0x024F,  // Latin Extended-A + Latin Extended-B (Spanish, etc.)
+        0x0370, 0x03FF,  // Greek and Coptic
+        0x0400, 0x04FF,  // Cyrillic (Russian, Ukrainian, etc.)
+        0x0500, 0x052F,  // Cyrillic Supplement
         0x2000, 0x206F,  // General Punctuation (em dash, ellipsis, etc.)
         0x2190, 0x21FF,  // Arrows (includes ⇄ U+21C4, ↻ U+21BB)
         0x2200, 0x22FF,  // Mathematical Operators (includes ≈ U+2248)
@@ -269,6 +272,36 @@ ImFont* Typography::loadFont(ImGuiIO& io, int weight, float size, const char* na
     
     if (font) {
         DEBUG_LOGF("Typography: Loaded %s (%.0fpx) as '%s'\n", name, size, cfg.Name);
+        
+        // Merge CJK fallback glyphs (Chinese/Japanese/Korean) from subset font
+        if (g_noto_cjk_subset_size > 0) {
+            void* cjkCopy = IM_ALLOC(g_noto_cjk_subset_size);
+            memcpy(cjkCopy, g_noto_cjk_subset_data, g_noto_cjk_subset_size);
+            
+            ImFontConfig cjkCfg;
+            cjkCfg.FontDataOwnedByAtlas = true;
+            cjkCfg.MergeMode = true;  // merge into the font we just loaded
+            cjkCfg.OversampleH = 1;
+            cjkCfg.OversampleV = 1;
+            cjkCfg.PixelSnapH = true;
+            cjkCfg.GlyphMinAdvanceX = 0;
+            // CJK Unified Ideographs + Hiragana + Katakana + Hangul + fullwidth punctuation
+            static const ImWchar cjkRanges[] = {
+                0x2E80, 0x2FDF,  // CJK Radicals
+                0x3000, 0x30FF,  // CJK Symbols, Hiragana, Katakana
+                0x3100, 0x312F,  // Bopomofo
+                0x31F0, 0x31FF,  // Katakana Extensions
+                0x3400, 0x4DBF,  // CJK Extension A
+                0x4E00, 0x9FFF,  // CJK Unified Ideographs
+                0xAC00, 0xD7AF,  // Hangul Syllables
+                0xFF00, 0xFFEF,  // Fullwidth Forms
+                0,
+            };
+            cjkCfg.GlyphRanges = cjkRanges;
+            snprintf(cjkCfg.Name, sizeof(cjkCfg.Name), "NotoSansCJK %.0fpx (merge)", size);
+            
+            io.Fonts->AddFontFromMemoryTTF(cjkCopy, g_noto_cjk_subset_size, size, &cjkCfg);
+        }
     } else {
         DEBUG_LOGF("Typography: Failed to load %s\n", name);
         IM_FREE(fontDataCopy);