feat: integrate custom font

main.cpp

@@ -1,5 +1,7 @@
 #include <QApplication>
 #include <QFile>
+#include <QFontDatabase>
+#include <QFont>
 #include "src/MainWindow.h"
 #include <QCoreApplication>
 
@@ -11,6 +13,16 @@ int main(int argc, char *argv[])
 
     QApplication a(argc, argv);
 
+    // Load Plus Jakarta Sans fonts
+    int regularFontId = QFontDatabase::addApplicationFont(":/assets/Plus_Jakarta_Sans/PlusJakartaSans-VariableFont_wght.ttf");
+    int italicFontId = QFontDatabase::addApplicationFont(":/assets/Plus_Jakarta_Sans/PlusJakartaSans-Italic-VariableFont_wght.ttf");
+
+    if (regularFontId != -1 && italicFontId != -1) {
+        // Set as application-wide default font
+        QFont appFont("Plus Jakarta Sans", 13);
+        a.setFont(appFont);
+    }
+
     // Load reMarkable e-ink stylesheet
     // QFile styleFile(":/styles/remarkable.qss");
     // if (styleFile.open(QFile::ReadOnly | QFile::Text)) {