refactor(fc2c-i): sweep blueprints + ml tasks onto shared get_session (covers tasks/ml.py, a survey gap)

backend/app/api/ml_admin.py

@@ -2,22 +2,11 @@
 
 from quart import Blueprint, jsonify, request
 
-from ..extensions import make_engine, make_session_factory
+from ..extensions import get_session
 from ..models import MLSettings
 
 ml_admin_bp = Blueprint("ml_admin", __name__, url_prefix="/api/ml")
 
-_engine = None
-_Session = None
-
-
-def _session_factory():
-    global _engine, _Session
-    if _engine is None:
-        _engine = make_engine()
-        _Session = make_session_factory(_engine)
-    return _Session
-
 
 _EDITABLE = (
     "suggestion_threshold_artist",
@@ -33,8 +22,7 @@ _EDITABLE = (
 async def get_settings():
     from sqlalchemy import select
 
-    Session = _session_factory()
-    async with Session() as session:
+    async with get_session() as session:
         s = (
             await session.execute(select(MLSettings).where(MLSettings.id == 1))
         ).scalar_one()
@@ -59,8 +47,7 @@ async def patch_settings():
     body = await request.get_json()
     if not isinstance(body, dict):
         return jsonify({"error": "body must be an object"}), 400
-    Session = _session_factory()
-    async with Session() as session:
+    async with get_session() as session:
         s = (
             await session.execute(select(MLSettings).where(MLSettings.id == 1))
         ).scalar_one()