Make enable_direct_download model field optional

Rendering it as a required boolean forced every client object-store test
fixture and mock to supply the field. Make ConcreteObjectStoreModel's
enable_direct_download Optional so it is generated as an optional
property (boolean | null) on both the model and its
UserConcreteObjectStoreModel subclass; to_model still reports the real
boolean value.

client/packages/api-client/src/schema/schema.ts

@@ -9126,11 +9126,8 @@ export interface components {
             description?: string | null;
             /** Device */
             device?: string | null;
-            /**
-             * Enable Direct Download
-             * @default false
-             */
-            enable_direct_download: boolean;
+            /** Enable Direct Download */
+            enable_direct_download?: boolean | null;
             /** Name */
             name?: string | null;
             /** Object Expires After Days */
@@ -25306,11 +25303,8 @@ export interface components {
             description?: string | null;
             /** Device */
             device?: string | null;
-            /**
-             * Enable Direct Download
-             * @default false
-             */
-            enable_direct_download: boolean;
+            /** Enable Direct Download */
+            enable_direct_download?: boolean | null;
             /** Hidden */
             hidden: boolean;
             /** Name */

lib/galaxy/objectstore/__init__.py

@@ -1836,7 +1836,7 @@ class ConcreteObjectStoreModel(BaseModel):
     quota: QuotaModel
     badges: list[BadgeDict]
     device: str | None = None
-    enable_direct_download: bool = False
+    enable_direct_download: bool | None = None
     object_expires_after_days: int | None = None