fix(@angular/cli): always install package during ng add to inspect manifest on disk for schematics

Private package registries such as GitHub Packages frequently strip out custom non-npm metadata properties (such as schematics and ng-add) from their remote API responses. Previously, ng add skipped confirming and installing a package if the registry metadata did not report hasSchematics, causing ng add to fail on first run.

This commit removes the early skip condition based on registry metadata so ng add always installs the target package to inspect its physical manifest on disk. If no schematics are found after installation, the CLI cleanly removes the temporary dependency.

Closes #33060

Author: alan-agius4

packages/angular/cli/src/commands/add/cli.ts

@@ -224,29 +224,12 @@ export default class AddCommandModule
         {
           title: 'Confirming installation',
           enabled: !skipConfirmation && !options.dryRun,
-          skip: (context) => {
-            if (context.hasSchematics) {
-              return false;
-            }
-
-            return `The ${color.blue(context.packageIdentifier.toString())} package does not provide \`ng add\` actions.`;
-          },
           task: (context, task) => this.confirmInstallationTask(context, task),
           rendererOptions: { persistentOutput: true },
         },
         {
           title: 'Installing package',
           skip: (context) => {
-            if (!context.hasSchematics) {
-              const builtInSchematic =
-                BUILT_IN_SCHEMATICS[
-                  context.packageIdentifier.name as keyof typeof BUILT_IN_SCHEMATICS
-                ];
-              if (builtInSchematic) {
-                return `Skipping package installation.`;
-              }
-            }
-
             if (context.dryRun) {
               return `Skipping package installation. Would install package ${color.blue(
                 context.packageIdentifier.toString(),
@@ -278,6 +261,9 @@ export default class AddCommandModule
               if (localManifest['ng-add']?.save === false) {
                 shouldCleanUp = true;
               }
+            } else {
+              await this.cleanUpTemporaryDependency(result.collectionName);
+              shouldCleanUp = false;
             }
           } catch {}
         }
@@ -305,6 +291,9 @@ export default class AddCommandModule
           const builtInSchematic =
             BUILT_IN_SCHEMATICS[packageName as keyof typeof BUILT_IN_SCHEMATICS];
           if (builtInSchematic) {
+            logger.info(
+              `The ${color.blue(packageName)} package does not provide \`ng add\` actions.`,
+            );
             logger.info('The Angular CLI will use built-in actions to add it to your project.');
 
             return this.executeSchematic({