feat: factory de conexao MySQL

tests/test_db_connection.py

@@ -0,0 +1,17 @@
+"""
+Requer o container de dev rodando (licenciamento-mysql-dev, porta 3307 —
+ver licenciamento-n8n/docs/configurar-banco-sistema.md). tests/conftest.py
+já configura as env vars de conexão com os mesmos defaults do .env.example.
+"""
+from app.db.connection import get_connection
+
+
+def test_conexao_abre_e_consulta():
+    conn = get_connection()
+    try:
+        with conn.cursor() as cur:
+            cur.execute("SELECT 1 AS um")
+            row = cur.fetchone()
+            assert row == {"um": 1}
+    finally:
+        conn.close()