refactor: reorganize memory-service into app/ directory structure

- Move models.py, schemas.py, crud.py, main.py to app/
- Update imports to use app.* prefix
- Update README with new structure
- Fix uvicorn run command for new structure

services/memory-service/README.md

@@ -26,11 +26,11 @@ cp .env.example .env
 ## Запуск
 
 ```bash
-# Development
-uvicorn main:app --reload --host 0.0.0.0 --port 8000
+# Development (з кореня services/memory-service/)
+uvicorn app.main:app --reload --host 0.0.0.0 --port 8000
 
 # Production
-uvicorn main:app --host 0.0.0.0 --port 8000 --workers 4
+uvicorn app.main:app --host 0.0.0.0 --port 8000 --workers 4
 ```
 
 ## API Endpoints