frontend-app-api: extract Mutable to common internal type in graph

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/frontend-app-api/src/wiring/graph/buildAppGraph.ts

@@ -14,11 +14,7 @@
  * limitations under the License.
  */
 
-import { AppNode, AppNodeEdges, AppNodeSpec } from './types';
-
-type Mutable<T> = {
-  -readonly [P in keyof T]: T[P];
-};
+import { AppNode, AppNodeEdges, AppNodeSpec, Mutable } from './types';
 
 /**
  * Build the app graph by iterating through all node specs and constructing the app

packages/frontend-app-api/src/wiring/graph/types.ts

@@ -20,6 +20,11 @@ import {
   ExtensionDataRef,
 } from '@backstage/frontend-plugin-api';
 
+/** @internal */
+export type Mutable<T> = {
+  -readonly [P in keyof T]: T[P];
+};
+
 /**
  * The specification for this node in the app graph.
  * @public