Enhance logging and conditional rendering in VocabService and VocabLessonView

- Added detailed logging in VocabService for lesson retrieval, including lesson ID, title, and exercise count.
- Improved conditional rendering in VocabLessonView to handle cases where grammar exercises may not be present, enhancing user experience.
- Updated logging in VocabLessonView to provide insights into loaded lessons and exercises, aiding in debugging and monitoring.

check-vocab-schema.sql

@@ -0,0 +1,38 @@
+-- ============================================
+-- Prüfe ob alle notwendigen Spalten vorhanden sind
+-- ============================================
+-- Führe diese Queries auf dem Server aus, um zu prüfen, ob alles vorhanden ist
+
+-- Prüfe native_language_id in vocab_course
+SELECT 
+    column_name, 
+    data_type, 
+    is_nullable
+FROM information_schema.columns 
+WHERE table_schema = 'community' 
+  AND table_name = 'vocab_course' 
+  AND column_name = 'native_language_id';
+
+-- Prüfe cultural_notes in vocab_course_lesson
+SELECT 
+    column_name, 
+    data_type, 
+    is_nullable
+FROM information_schema.columns 
+WHERE table_schema = 'community' 
+  AND table_name = 'vocab_course_lesson' 
+  AND column_name = 'cultural_notes';
+
+-- Prüfe ob vocab_grammar_exercise Tabelle existiert
+SELECT EXISTS (
+    SELECT FROM information_schema.tables 
+    WHERE table_schema = 'community' 
+    AND table_name = 'vocab_grammar_exercise'
+);
+
+-- Prüfe ob vocab_grammar_exercise_type Tabelle existiert
+SELECT EXISTS (
+    SELECT FROM information_schema.tables 
+    WHERE table_schema = 'community' 
+    AND table_name = 'vocab_grammar_exercise_type'
+);