Resolve linter contradictions: consolidate config, fix isort first-party, pylint 10/10

Agent-Logs-Url: https://github.com/christianlouis/dmarq/sessions/1e4a1f06-55b9-4040-853e-6aaf9ee574c8

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

backend/app/core/database.py

@@ -1,10 +1,11 @@
 from typing import Generator
 
-from app.core.config import get_settings
 from sqlalchemy import create_engine
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import sessionmaker
 
+from app.core.config import get_settings
+
 settings = get_settings()
 
 # Configure SQLAlchemy