[DEMO] resetDataset cablato a DemoSeedService (reset reale dataset demo/sandbox)

- application/services/DemoSeedService.php: logica seed/clone golden #151 -> 996001/996002 (riusabile)
- DemoController::resetDataset: re-seed reale via service (?scope=demo|sandbox|default both), non piu stub
- scripts/seed-demo-dataset.php: thin CLI wrapper sul service
Testato prod: POST /api/demo/reset-dataset (X-Internal-Key) scope=sandbox -> 200, 996002 ri-seedata.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

application/controllers/DemoController.php

@@ -10,6 +10,7 @@
  */
 
 require_once __DIR__ . '/BaseController.php';
+require_once __DIR__ . '/../services/DemoSeedService.php';
 
 class DemoController extends BaseController
 {
@@ -180,12 +181,21 @@ class DemoController extends BaseController
             $this->jsonError('Non autorizzato', 401, 'UNAUTHORIZED');
         }
 
-        // TODO Fase 1 (increment dataset): DELETE + re-seed org demo 996001 da seed idempotente.
+        // Reset idempotente del dataset demo (clona la golden #151 in 996001/996002).
+        // ?scope=demo → solo 996001 (read-only) | ?scope=sandbox → solo 996002 | default: entrambe.
+        $scope = (string) $this->getParam('scope', '');
+        $targets = $scope === 'demo'    ? [996001 => DemoSeedService::TARGETS[996001]]
+                 : ($scope === 'sandbox' ? [996002 => DemoSeedService::TARGETS[996002]]
+                 : DemoSeedService::TARGETS);
+
+        $result = DemoSeedService::seed($targets);
+        $failed = array_filter($result, fn($v) => str_starts_with($v, 'errore'));
+
         $this->jsonSuccess([
-            'reset'        => 'pending_implementation',
-            'company_ids'  => [self::DEMO_ORG_ID],
-            'note'         => 'Logica di reset dataset demo in arrivo (seed isolato org 996001).',
-        ], 'Reset demo (stub)');
+            'reset'       => empty($failed) ? 'done' : 'partial',
+            'company_ids' => array_keys($result),
+            'detail'      => $result,
+        ], empty($failed) ? 'Dataset demo reimpostato' : 'Reset demo parziale (vedi detail)', empty($failed) ? 200 : 207);
     }
 
     // ═══ Helpers ═════════════════════════════════════════════════════════════