Move known plugin package constants from cli-common to cli-internal

The known plugin package ID mappings don't need to be part of the
public API surface. Move them to @internal/cli and update consumers.

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

packages/cli-internal/src/index.ts

@@ -31,3 +31,7 @@ export {
   resetSecretStore,
   type SecretStore,
 } from './secretStore';
+export {
+  knownBackendPluginPackageNameByPluginId,
+  knownFrontendPluginPackageNameByPluginId,
+} from './knownPluginPackages';

packages/cli-internal/src/knownPluginPackages.ts

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2025 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.
+ */
+
+const knownBackendPluginIds = [
+  'app',
+  'auth',
+  'catalog',
+  'events',
+  'kubernetes',
+  'notifications',
+  'permission',
+  'proxy',
+  'scaffolder',
+  'search',
+  'signals',
+  'techdocs',
+];
+
+// Only includes plugin IDs that have a corresponding frontend package; some plugins are backend-only and not listed here.
+const knownFrontendPluginIds = [
+  'app',
+  'auth',
+  'catalog',
+  'kubernetes',
+  'notifications',
+  'scaffolder',
+  'search',
+  'signals',
+  'techdocs',
+];
+
+/**
+ * Maps known plugin IDs to their corresponding backend package names.
+ */
+export const knownBackendPluginPackageNameByPluginId: Record<string, string> =
+  Object.fromEntries(
+    knownBackendPluginIds.map(pluginId => [
+      pluginId,
+      `@backstage/plugin-${pluginId}-backend`,
+    ]),
+  );
+
+/**
+ * Maps known plugin IDs to their corresponding frontend package names.
+ */
+export const knownFrontendPluginPackageNameByPluginId: Record<string, string> =
+  Object.fromEntries(
+    knownFrontendPluginIds.map(pluginId => [
+      pluginId,
+      `@backstage/plugin-${pluginId}`,
+    ]),
+  );