[FEAT] Services API: full-snapshot endpoint + BigSim SSE wrapper

- ServicesController: nuovo endpoint GET /api/services/full-snapshot
  Aggrega gap-analysis, measures, incidents, training, deadlines,
  compliance-summary in una sola chiamata (reduce 6 round-trip → 1)
  Parametro ?days=N per finestra deadlines (default 30, max 365)

- public/index.php: route GET:fullSnapshot aggiunta all'action map services

- public/simulate-nis2-big.php: wrapper SSE per simulate-nis2-big.php
  Esegue il simulatore come sottoprocesso CLI con NIS2_SSE=1 e
  streama l'output al browser tramite Server-Sent Events

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/index.php

@@ -334,6 +334,7 @@ $actionMap = [
         'GET:incidents'              => 'incidents',
         'GET:training'               => 'training',
         'GET:deadlines'              => 'deadlines',
+        'GET:fullSnapshot'           => 'fullSnapshot',
     ],
 
     // ── WebhookController (CRUD keys + subscriptions) ──