[FIX] Qdrant URL hostname drift-proof (RAG produzione) + recreate app

L'IP hardcoded Qdrant 172.21.0.5 era driftato a .3 (container senza IP statico) e
con php-fpm clear_env=no la env QDRANT_URL=172.21.0.5 (morta) veniva usata -> RAG web rotta.
Fix: QDRANT_URL e fallback VectorService usano l'hostname http://nis2-qdrant:6333,
risolto via Docker DNS sia in CLI sia in php-fpm. Verificato retrieval end-to-end (287 chunk).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docker/docker-compose.yml

@@ -28,7 +28,7 @@ services:
       - ANTHROPIC_API_KEY=${ANTHROPIC_API_KEY}
       - VOYAGE_API_KEY=${VOYAGE_API_KEY}
       - VOYAGE_MODEL=${VOYAGE_MODEL:-voyage-3-lite}
-      - QDRANT_URL=http://172.21.0.5:6333
+      - QDRANT_URL=http://nis2-qdrant:6333
       - VAULT_STEWARD_URL=https://vault-steward:8443
       - VAULT_APP_TOKEN=${VAULT_APP_TOKEN_NIS2}
       - VAULT_PREFIX=tier1__nis2-app__