Add @internal/cli package for opaque CLI types

Move OpaqueCliPlugin to a new @internal/cli inline package, following the
same pattern as @internal/frontend. Both cli-plugin-api and cli import it
directly, and it gets bundled into their dists at build time.

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

packages/cli-internal/.eslintrc.js

@@ -0,0 +1 @@
+module.exports = require('@backstage/cli/config/eslint-factory')(__dirname);

packages/cli-internal/catalog-info.yaml

@@ -0,0 +1,9 @@
+apiVersion: backstage.io/v1alpha1
+kind: Component
+metadata:
+  name: internal-cli
+  title: '@internal/cli'
+spec:
+  lifecycle: experimental
+  type: backstage-node-library
+  owner: tooling-maintainers

packages/cli-internal/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "@internal/cli",
+  "version": "0.0.1",
+  "backstage": {
+    "role": "node-library",
+    "inline": true
+  },
+  "private": true,
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/backstage/backstage",
+    "directory": "packages/cli-internal"
+  },
+  "license": "Apache-2.0",
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "files": [
+    "dist"
+  ],
+  "scripts": {
+    "lint": "backstage-cli package lint",
+    "test": "backstage-cli package test"
+  },
+  "dependencies": {
+    "@backstage/cli-plugin-api": "workspace:^"
+  },
+  "devDependencies": {
+    "@backstage/cli": "workspace:^"
+  }
+}

packages/cli-internal/src/InternalCliPlugin.ts

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2024 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { BackstageCommand, CliPlugin } from '@backstage/cli-plugin-api';
+import { OpaqueType } from '@internal/opaque';
+
+export const OpaqueCliPlugin = OpaqueType.create<{
+  public: CliPlugin;
+  versions: {
+    readonly version: 'v1';
+    readonly description: string;
+    init: (registry: {
+      addCommand: (command: BackstageCommand) => void;
+    }) => Promise<void>;
+  };
+}>({
+  type: '@backstage/CliPlugin',
+  versions: ['v1'],
+});

packages/cli-internal/src/index.ts

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2024 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export { OpaqueCliPlugin } from './InternalCliPlugin';