Refactor code structure for improved readability and maintainability

pyproject.toml

@@ -3,7 +3,7 @@ name = "sdb"
 version = "2.0.0"
 description = "Backend for the SDB v2"
 readme = "README.md"
-requires-python = ">=3.13"
+requires-python = ">=3.12"
 dependencies = [
     "aiosqlite==0.21.0",
     "apscheduler==3.11.0",
@@ -29,7 +29,7 @@ dev-dependencies = [
     "mypy==1.17.1",
     "pytest==8.4.1",
     "pytest-asyncio==1.1.0",
-    "ruff==0.12.9",
+    "ruff==0.12.10",
 ]
 
 [tool.mypy]
@@ -37,7 +37,7 @@ strict = true
 exclude = ["venv", ".venv", "alembic"]
 
 [tool.ruff]
-target-version = "py313"
+target-version = "py312"
 exclude = ["alembic"]
 
 [tool.ruff.lint]