fix(cloud): persist configuration and load release-image packages (#18335)

Land the approved Cloud configuration and release-image package stack.

Includes the separately reviewed adapter settings (#18335), external adapters (#18333), bundled plugins (#18336), startup configuration (#18339), and migration/package checks (#18341).

Includes the final image-owned loader and linked-dependency inventory corrections.

Verified stack head: 462716170d.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

server/src/services/adapter-code-policy.ts

@@ -0,0 +1,10 @@
+import { forbidden } from "../errors.js";
+import { isCloudManagedInstance } from "./cloud-instance.js";
+
+export function assertExternalAdapterCodeAllowed(): void {
+  if (isCloudManagedInstance()) {
+    throw forbidden("Adapter installation is platform-managed on cloud-managed instances", {
+      code: "adapter_install_platform_managed",
+    });
+  }
+}