feat: CJK font rendering, force quit confirmation, settings i18n

- Rebuild CJK font subset (1421 glyphs) and convert CFF→TTF for
  stb_truetype compatibility, fixing Chinese/Japanese/Korean rendering
- Add force quit confirmation dialog with cancel/confirm actions
- Show force quit tooltip immediately on hover (no delay)
- Translate hardcoded English strings in settings dropdowns
  (auto-lock timeouts, slider "Off" labels)
- Fix mojibake en-dashes in 7 translation JSON files
- Add helper scripts: build_cjk_subset, convert_cjk_to_ttf,
  check_font_coverage, fix_mojibake

src/ui/material/typography.cpp

@@ -300,7 +300,14 @@ ImFont* Typography::loadFont(ImGuiIO& io, int weight, float size, const char* na
             cjkCfg.GlyphRanges = cjkRanges;
             snprintf(cjkCfg.Name, sizeof(cjkCfg.Name), "NotoSansCJK %.0fpx (merge)", size);
             
-            io.Fonts->AddFontFromMemoryTTF(cjkCopy, g_noto_cjk_subset_size, size, &cjkCfg);
+            ImFont* mergeResult = io.Fonts->AddFontFromMemoryTTF(cjkCopy, g_noto_cjk_subset_size, size, &cjkCfg);
+            if (mergeResult) {
+                DEBUG_LOGF("Typography: Merged CJK (%u bytes) into %s OK\n",
+                           g_noto_cjk_subset_size, name);
+            } else {
+                DEBUG_LOGF("Typography: WARNING — CJK merge FAILED for %s (size=%u)\n",
+                           name, g_noto_cjk_subset_size);
+            }
         }
     } else {
         DEBUG_LOGF("Typography: Failed to load %s\n", name);