Add Vocab Trainer feature with routing, database schema, and translations

- Introduced Vocab Trainer functionality, including new routes for managing languages and chapters.
- Implemented database schema for vocab-related tables to ensure data integrity.
- Updated navigation and UI components to include Vocab Trainer in the social network menu.
- Added translations for Vocab Trainer in both German and English locales, enhancing user accessibility.

backend/controllers/navigationController.js

@@ -4,6 +4,7 @@ import UserRight from '../models/community/user_right.js';
 import UserRightType from '../models/type/user_right.js';
 import UserParamType from '../models/type/user_param.js';
 import FalukantUser from '../models/falukant/data/user.js';
+import VocabService from '../services/vocabService.js';
 
 const menuStructure = {
     home: {
@@ -49,6 +50,11 @@ const menuStructure = {
                 visible: ["all"],
                 path: "/socialnetwork/gallery"
             },
+            vocabtrainer: {
+                visible: ["all"],
+                path: "/socialnetwork/vocab",
+                children: {}
+            },
             blockedUsers: {
                 visible: ["all"],
                 path: "/socialnetwork/blocked"
@@ -296,6 +302,7 @@ const menuStructure = {
 class NavigationController {
     constructor() {
         this.menu = this.menu.bind(this);
+        this.vocabService = new VocabService();
     }
 
     calculateAge(birthDate) {
@@ -365,6 +372,24 @@ class NavigationController {
             const age = this.calculateAge(birthDate);
             const rights = userRights.map(ur => ur.rightType?.title).filter(Boolean);
             const filteredMenu = await this.filterMenu(menuStructure, rights, age, user.id);
+
+            // Dynamisches Submenü: Treffpunkt → Vokabeltrainer → (Neue Sprache + abonnierte/angelegte)
+            // Wichtig: "Neue Sprache" soll IMMER sichtbar sein – auch wenn die DB-Abfrage (noch) fehlschlägt.
+            if (filteredMenu?.socialnetwork?.children?.vocabtrainer) {
+                const children = {
+                    newLanguage: { path: '/socialnetwork/vocab/new' },
+                };
+                try {
+                    const langs = await this.vocabService.listLanguagesForMenu(user.id);
+                    for (const l of langs) {
+                        children[`lang_${l.id}`] = { path: `/socialnetwork/vocab/${l.id}`, label: l.name };
+                    }
+                } catch (e) {
+                    console.warn('[menu] Konnte Vokabeltrainer-Sprachen nicht laden:', e?.message || e);
+                }
+                filteredMenu.socialnetwork.children.vocabtrainer.children = children;
+            }
+
             res.status(200).json(filteredMenu);
         } catch (error) {
             console.error('Error fetching menu:', error);