feat(fleet): add reviewed v1-to-v2 migration preview (#788)

packages/mosaic/src/cli-smoke.spec.ts

@@ -1,3 +1,5 @@
+import { spawnSync } from 'node:child_process';
+import { fileURLToPath } from 'node:url';
 import { describe, expect, it } from 'vitest';
 import { Command } from 'commander';
 import { registerBrainCommand } from '@mosaicstack/brain';
@@ -16,6 +18,8 @@ import { registerConfigCommand } from './commands/config.js';
 // without throwing. This is the "mosaic <cmd> --help exits 0" gate that
 // guards the sub-package CLI surface (CU-05-01..08) from silent breakage.
 
+const CLI_PATH = fileURLToPath(new URL('../dist/cli.js', import.meta.url));
+
 const REGISTRARS: Array<[string, (program: Command) => void]> = [
   ['auth', registerAuthCommand],
   ['brain', registerBrainCommand],
@@ -46,6 +50,40 @@ describe('sub-package CLI smoke (CU-05-10)', () => {
     });
   }
 
+  it.each(['source', 'decisions', 'observations'] as const)(
+    'production CLI emits one blocked JSON object for bare --%s',
+    (bareOption) => {
+      const args = [
+        CLI_PATH,
+        'fleet',
+        'migrate-v1',
+        'preview',
+        '--source=source',
+        '--decisions=decisions',
+        '--observations=observations',
+      ];
+      args[args.findIndex((argument) => argument.startsWith(`--${bareOption}=`))] =
+        `--${bareOption}`;
+
+      const result = spawnSync(process.execPath, args, { encoding: 'utf8' });
+      const outputLines = result.stdout.trim().split('\n');
+
+      expect(result.status).toBe(1);
+      expect(result.stderr).toBe('');
+      expect(outputLines).toHaveLength(1);
+      expect(JSON.parse(outputLines[0]!)).toEqual({
+        status: 'blocked',
+        blockers: [
+          {
+            code: 'missing-migration-preview-option-value',
+            path: `request.${bareOption}`,
+            detail: 'Required migration preview option value is missing.',
+          },
+        ],
+      });
+    },
+  );
+
   it('all nine sub-package commands coexist on a single program', () => {
     const program = new Command();
     for (const [, register] of REGISTRARS) register(program);