Cleanup: Delete ALL 242 shims, update ALL consumer imports

klausur-service: 183 shims deleted, 26 test files + 8 source files updated
backend-lehrer: 59 shims deleted, main.py + 8 source files updated

All imports now use the new package paths directly.
Zero shims remaining in the entire codebase.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend-lehrer/main.py

@@ -50,7 +50,7 @@ async def lifespan(app: FastAPI):
     logger.info("Backend-Lehrer starting up  (DB search_path=lehrer,core,public)")
     # Initialize vocabulary tables
     try:
-        from vocabulary_db import init_vocabulary_tables
+        from vocabulary.db import init_vocabulary_tables
         await init_vocabulary_tables()
     except Exception as e:
         logger.warning(f"Vocabulary tables init failed (non-critical): {e}")
@@ -97,70 +97,70 @@ from classroom_api import router as classroom_router
 app.include_router(classroom_router, prefix="/api/classroom")
 
 # --- 2. State Engine (Begleiter-Modus mit Phasen und Antizipation) ---
-from state_engine_api import router as state_engine_router
+from classroom.state_engine_api import router as state_engine_router
 app.include_router(state_engine_router, prefix="/api")
 
 # --- 3. Worksheets & Corrections ---
-from worksheets_api import router as worksheets_router
+from worksheets.api import router as worksheets_router
 app.include_router(worksheets_router, prefix="/api")
 
-from correction_api import router as correction_router
+from correction.api import router as correction_router
 app.include_router(correction_router, prefix="/api")
 
 # --- 4. Learning Units ---
-from learning_units_api import router as learning_units_router
+from units.learning_api import router as learning_units_router
 app.include_router(learning_units_router, prefix="/api")
 
 # --- 4b. Learning Progress ---
-from progress_api import router as progress_router
+from api.progress import router as progress_router
 app.include_router(progress_router, prefix="/api")
 
 # --- 4c. Vocabulary Catalog ---
-from vocabulary_api import router as vocabulary_router
+from vocabulary.api import router as vocabulary_router
 app.include_router(vocabulary_router, prefix="/api")
 
 # --- 4d. User Language Preferences ---
-from user_language_api import router as user_language_router
+from api.user_language import router as user_language_router
 app.include_router(user_language_router, prefix="/api")
 
-from unit_api import router as unit_router
+from units.api import router as unit_router
 app.include_router(unit_router)  # Already has /api/units prefix
 
-from unit_analytics_api import router as unit_analytics_router
+from units.analytics_api import router as unit_analytics_router
 app.include_router(unit_analytics_router)  # Already has /api/analytics prefix
 
 
-from recording_api import router as recording_api_router
+from recording.api import router as recording_api_router
 app.include_router(recording_api_router)  # Already has /api/recordings prefix
 
 
 # --- 6. Messenger ---
-from messenger_api import router as messenger_router
+from messenger.api import router as messenger_router
 app.include_router(messenger_router)  # Already has /api/messenger prefix
 
 # --- 7. Klausur & School Proxies ---
-from klausur_service_proxy import router as klausur_service_router
+from api.klausur_proxy import router as klausur_service_router
 app.include_router(klausur_service_router, prefix="/api")
 
-from school_api import router as school_api_router
+from api.school import router as school_api_router
 app.include_router(school_api_router, prefix="/api")
 
 # --- 8. Teacher Dashboard & Abitur Docs ---
-from abitur_docs_api import router as abitur_docs_router
+from abitur.api import router as abitur_docs_router
 app.include_router(abitur_docs_router, prefix="/api")
 
-from teacher_dashboard_api import router as teacher_dashboard_router
+from dashboard.api import router as teacher_dashboard_router
 app.include_router(teacher_dashboard_router)  # Already has /api/teacher prefix
 
 # --- 9. Certificates & Letters ---
-from certificates_api import router as certificates_router
+from letters.certificates_api import router as certificates_router
 app.include_router(certificates_router, prefix="/api")
 
-from letters_api import router as letters_router
+from letters.api import router as letters_router
 app.include_router(letters_router, prefix="/api")
 
 # --- 10. Game System ---
-from game_api import router as game_router
+from game.api import router as game_router
 app.include_router(game_router)  # Already has /api/game prefix
 
 # --- 11. AI Processor (OCR + Content generation) ---