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/sidebar.h

@@ -11,6 +11,7 @@
 #include "layout.h"
 #include "schema/ui_schema.h"
 #include "../embedded/IconsMaterialDesign.h"
+#include "../util/i18n.h"
 #include <cstdio>
 #include <cmath>
 
@@ -34,25 +35,35 @@ enum class NavPage {
 };
 
 struct NavItem {
-    const char* label;
+    const char* label;           // fallback label (English)
     NavPage     page;
-    const char* section_label;  // if non-null, render section label above this item
+    const char* section_label;   // if non-null, render section label above this item
+    const char* tr_key;          // i18n key for label
+    const char* section_tr_key;  // i18n key for section_label
 };
 
 inline const NavItem kNavItems[] = {
-    { "Overview",     NavPage::Overview, nullptr     },
-    { "Send",         NavPage::Send,     nullptr     },
-    { "Receive",      NavPage::Receive,  nullptr     },
-    { "History",      NavPage::History,  nullptr     },
-    { "Mining",       NavPage::Mining,   "TOOLS"     },
-    { "Market",       NavPage::Market,   nullptr     },
-    { "Console",      NavPage::Console,  "ADVANCED"  },
-    { "Network",      NavPage::Peers,    nullptr     },
-    { "Settings",     NavPage::Settings, nullptr     },
+    { "Overview",  NavPage::Overview, nullptr,    "overview", nullptr     },
+    { "Send",      NavPage::Send,     nullptr,    "send",     nullptr     },
+    { "Receive",   NavPage::Receive,  nullptr,    "receive",  nullptr     },
+    { "History",   NavPage::History,  nullptr,    "history",  nullptr     },
+    { "Mining",    NavPage::Mining,   "TOOLS",   "mining",   "tools"     },
+    { "Market",    NavPage::Market,   nullptr,    "market",   nullptr     },
+    { "Console",   NavPage::Console,  "ADVANCED","console",  "advanced"  },
+    { "Network",   NavPage::Peers,    nullptr,    "network",  nullptr     },
+    { "Settings",  NavPage::Settings, nullptr,    "settings", nullptr     },
 };
 static_assert(sizeof(kNavItems) / sizeof(kNavItems[0]) == (int)NavPage::Count_,
               "kNavItems must match NavPage::Count_");
 
+// Get translated nav label at runtime
+inline const char* NavLabel(const NavItem& item) {
+    return item.tr_key ? TR(item.tr_key) : item.label;
+}
+inline const char* NavSectionLabel(const NavItem& item) {
+    return item.section_tr_key ? TR(item.section_tr_key) : item.section_label;
+}
+
 // Get the Material Design icon string for a navigation page.
 inline const char* GetNavIconMD(NavPage page)
 {
@@ -541,7 +552,7 @@ inline bool RenderSidebar(NavPage& current, float sidebarWidth, float contentHei
             float olFsz = ScaledFontSize(olFont);
             dl->AddText(olFont, olFsz,
                         ImVec2(wp.x + sbSectionLabelPadLeft, labelY),
-                        ImGui::ColorConvertFloat4ToU32(olCol), item.section_label);
+                        ImGui::ColorConvertFloat4ToU32(olCol), NavSectionLabel(item));
             ImGui::Dummy(ImVec2(0, olFsz + 2.0f));
         } else if (item.section_label && !showLabels) {
             // Collapsed: thin separator instead of label
@@ -609,11 +620,19 @@ inline bool RenderSidebar(NavPage& current, float sidebarWidth, float contentHei
         ImU32 textCol = selected ? Primary() : OnSurfaceMedium();
 
         if (showLabels) {
-            // Measure total width of icon + gap + label, then center
+            // Measure total width of icon + gap + label, then center.
+            // If the translated label is too wide, shrink the font to fit.
             ImFont* font = selected ? Type().subtitle2() : Type().body2();
             float gap = iconLabelGap;
             float lblFsz = ScaledFontSize(font);
-            ImVec2 labelSz = font->CalcTextSizeA(lblFsz, 1000.0f, 0.0f, item.label);
+            float btnW = indMax.x - indMin.x;
+            float maxLabelW = btnW - iconS * 2.0f - gap - Layout::spacingXs() * 2;
+            ImVec2 labelSz = font->CalcTextSizeA(lblFsz, 1000.0f, 0.0f, NavLabel(item));
+            if (labelSz.x > maxLabelW && maxLabelW > 0) {
+                float shrink = maxLabelW / labelSz.x;
+                lblFsz *= shrink;
+                labelSz = font->CalcTextSizeA(lblFsz, 1000.0f, 0.0f, NavLabel(item));
+            }
             float totalW = iconS * 2.0f + gap + labelSz.x;
             float btnCX = (indMin.x + indMax.x) * 0.5f;
             float startX = btnCX - totalW * 0.5f;
@@ -625,7 +644,7 @@ inline bool RenderSidebar(NavPage& current, float sidebarWidth, float contentHei
             ImVec4 lc = ImGui::ColorConvertU32ToFloat4(textCol);
             lc.w *= expandFrac;
             dl->AddText(font, lblFsz, ImVec2(labelX, textY),
-                        ImGui::ColorConvertFloat4ToU32(lc), item.label);
+                        ImGui::ColorConvertFloat4ToU32(lc), NavLabel(item));
         } else {
             float iconCX = (indMin.x + indMax.x) * 0.5f;
             DrawNavIcon(dl, item.page, iconCX, iconCY, iconS, textCol);
@@ -633,7 +652,7 @@ inline bool RenderSidebar(NavPage& current, float sidebarWidth, float contentHei
 
         // Tooltip when collapsed + hovered
         if (!showLabels && hovered) {
-            ImGui::SetTooltip("%s", item.label);
+            ImGui::SetTooltip("%s", NavLabel(item));
         }
 
         // ---- Badge indicator ----