refactor(bisaya-course): enhance pedagogy logic for German lessons

- Updated the `getGermanForBisayaLessonPedagogy` function to include lesson titles for improved didactic mode determination, specifically adding support for 'contrast_training'.
- Modified multiple scripts to utilize the updated pedagogy function, ensuring consistent application of the new logic across various course phases.
- Enhanced the VocabService to recognize and handle 'contrast_training' as a didactic mode, improving lesson management and user experience.
- Updated UI components to reflect the new didactic mode, ensuring clarity in lesson presentation.

backend/services/vocabService.js

@@ -620,11 +620,32 @@ export default class VocabService {
   }
 
   _inferLessonDidacticMode(plainLesson) {
-    if (plainLesson.didacticMode) {
-      return plainLesson.didacticMode;
-    }
     const lessonType = String(plainLesson.lessonType || '').toLowerCase();
     const title = String(plainLesson.title || '').toLowerCase();
+    const storedMode = String(plainLesson.didacticMode || '').trim();
+
+    const isContrastTraining = lessonType === 'grammar' && [
+      'kontrast',
+      'fehlertraining',
+      ' / ',
+      'nicht / kein',
+      'der / die / das',
+      'wo / wohin',
+      'du / sie',
+      'haben / sein',
+      'ich bin / ich habe',
+      'ich bin / ich heiße / ich komme'
+    ].some((marker) => title.includes(marker));
+
+    if (storedMode && storedMode !== 'pattern_drill') {
+      return storedMode;
+    }
+    if (isContrastTraining) {
+      return 'contrast_training';
+    }
+    if (storedMode) {
+      return storedMode;
+    }
     if (title.includes('abschluss') || title.includes('prüfung') || title.includes('test')) {
       return 'checkpoint';
     }
@@ -648,6 +669,7 @@ export default class VocabService {
       return plainLesson.difficultyWeight;
     }
     switch (didacticMode) {
+      case 'contrast_training':
       case 'pattern_drill':
         return 3;
       case 'guided_dialogue':
@@ -666,6 +688,8 @@ export default class VocabService {
       return plainLesson.newUnitTarget;
     }
     switch (didacticMode) {
+      case 'contrast_training':
+        return 3;
       case 'core_input':
         return 8;
       case 'guided_dialogue':
@@ -692,6 +716,8 @@ export default class VocabService {
         return 90;
       case 'checkpoint':
         return 70;
+      case 'contrast_training':
+        return 70;
       case 'pattern_drill':
         return 55;
       case 'real_life_scenario':