Pin Minecraft 26.3 and add safe Orion managed deployment support

dashboard/src/server/managed.ts

@@ -0,0 +1,11 @@
+import { env } from "./env";
+
+export class ManagedDeploymentError extends Error {
+  constructor() {
+    super("This deployment is managed by Komodo. Change its reviewed configuration in homelab-infra.");
+  }
+}
+
+export function assertDeploymentEditable(): void {
+  if (env.managed) throw new ManagedDeploymentError();
+}