feat(vocab): add dashboard learning summary and related endpoints

- Introduced `getDashboardLearningSummary` method in `VocabService` to provide a compact overview of enrolled courses and current lessons for users.
- Updated `vocabController` to include a new route for the dashboard widget, allowing users to access their learning summary.
- Enhanced `vocabRouter` to route requests for the new dashboard widget endpoint.
- Added localization support for the new dashboard features across multiple languages, improving user engagement and accessibility.
- Updated UI components to integrate the new dashboard widget, ensuring a seamless user experience.

frontend/src/i18n/locales/es/falukant.json

@@ -1261,6 +1261,20 @@
                 "upcoming": "Cargos pendientes de (re)elección",
                 "elections": "Elecciones"
             },
+            "benefits": {
+                "daily_salary": "Estipendio diario (una vez al día): unos {amount}",
+                "tax_exemption": "Exención fiscal: {regions}",
+                "tax_exemption_all": "Exención fiscal: todos los niveles regionales",
+                "generic": "Ventaja ({code})"
+            },
+            "regionLevels": {
+                "city": "Ciudad",
+                "county": "Condado",
+                "shire": "Condado (shire)",
+                "markgrave": "Margraviato",
+                "duchy": "Ducado",
+                "country": "País"
+            },
             "current": {
                 "office": "Cargo",
                 "region": "Región",

frontend/src/i18n/locales/es/general.json

@@ -92,6 +92,16 @@
         },
         "falukant": {
             "emptyValue": "—"
+        },
+        "vocabCourses": {
+            "empty": "Aún no estás inscrito en ningún curso de vocabulario.",
+            "browseCourses": "Ver cursos",
+            "unnamedCourse": "Curso sin título",
+            "lessonLine": "Lección n.º {number}: {title}",
+            "noLessons": "Este curso aún no tiene lecciones.",
+            "allDone": "Todas las lecciones completadas",
+            "openLesson": "Ir a la lección",
+            "openCourse": "Abrir curso"
         }
     },
     "gender": {

frontend/src/i18n/locales/es/home.json

@@ -23,7 +23,8 @@
                 "news": "Noticias",
                 "birthdays": "Cumpleaños",
                 "upcoming": "Próximas citas",
-                "calendar": "Calendario"
+                "calendar": "Calendario",
+                "vocabCourses": "Cursos de idiomas"
             },
             "overview": {
                 "activeWidgetsLabel": "Widgets activos",