Fix empty reply: remove gunicorn preload, isolate DB init from workers

Co-authored-by: Cursor <cursoragent@cursor.com>

gunicorn.conf.py

@@ -0,0 +1,12 @@
+bind = "0.0.0.0:8000"
+workers = 2
+timeout = 120
+accesslog = "-"
+errorlog = "-"
+capture_output = True
+
+
+def post_fork(server, worker):
+    from app import db
+
+    db.engine.dispose()