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

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

app/__init__.py

@@ -30,6 +30,7 @@ def create_app(setup_database=True):
         "postgresql://photohost:photohost_secret@localhost:5432/photohost",
     )
     app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
+    app.config["SQLALCHEMY_ENGINE_OPTIONS"] = {"pool_pre_ping": True}
     app.config["UPLOAD_FOLDER"] = os.getenv("UPLOAD_FOLDER", "uploads")
     app.config["MAX_CONTENT_LENGTH"] = int(os.getenv("MAX_UPLOAD_MB", "10")) * 1024 * 1024
     app.config["ALLOWED_EXTENSIONS"] = {"png", "jpg", "jpeg", "gif", "webp", "bmp"}
@@ -68,25 +69,26 @@ def create_app(setup_database=True):
         except Exception:
             return {"site_banners": {}}
 
-    with app.app_context():
-        from app.models import (  # noqa: F401
-            AdBanner,
-            Folder,
-            FolderInvite,
-            FolderMember,
-            PasswordResetToken,
-            Photo,
-            SiteSettings,
-            User,
-            UserGroup,
-        )
+    if setup_database:
+        with app.app_context():
+            from app.models import (  # noqa: F401
+                AdBanner,
+                Folder,
+                FolderInvite,
+                FolderMember,
+                PasswordResetToken,
+                Photo,
+                SiteSettings,
+                User,
+                UserGroup,
+            )
 
-        db.create_all()
+            db.create_all()
 
-        if setup_database and os.getenv("SKIP_DB_INIT") != "1":
-            from app.bootstrap import run_database_setup
+            if os.getenv("SKIP_DB_INIT") != "1":
+                from app.bootstrap import run_database_setup
 
-            run_database_setup(app)
+                run_database_setup(app)
 
     return app