fix(slink): fix DB init order — migrations for roles, schema:update for event_store

- Event store migrations use PostgreSQL-specific SQL (SERIAL, UUID) that
  fails on SQLite — replaced with doctrine:schema:update --force
- Run messenger:setup-transports BEFORE event_store schema to avoid
  messenger_messages table conflict
- Read model migrations (--em=read_model) include role seeding (ROLE_USER,
  ROLE_ADMIN) which doctrine:schema:create skips
- Fix default_credentials in json to match script (admin@slink.local)

json/slink.json

@@ -28,7 +28,7 @@
     }
   ],
   "default_credentials": {
-    "username": "admin@localhost",
+    "username": "admin@slink.local",
     "password": "auto-generated"
   },
   "notes": [