feat: migrate InfluxDB and Grafana from digital-twin/ to smart-city/ stack

- docker-compose.influxdb.yml: InfluxDB v2 on smartcity-shared + traefik-public
- docker-compose.grafana.yml: Grafana 10.2 on smartcity-shared + traefik-public
- grafana/provisioning/: dashboards + datasources updated for smart-city
- pulsar/docker-compose.yml: added smartcity-shared network for simulator access

Services migrated (preserving existing volumes):
  - digital-twin-influxdb → smart-city-influxdb
  - digital-twin-grafana  → smart-city-grafana

Traefik routes updated:
  - influxdb.digitribe.fr → smart-city-influxdb:8086
  - grafana.digitribe.fr  → smart-city-grafana:3000

grafana/provisioning/dashboards/dashboards.yml

@@ -0,0 +1,13 @@
+apiVersion: 1
+
+providers:
+  - name: 'Smart City Dashboards'
+    orgId: 1
+    folder: 'Smart City'
+    folderUid: 'smart-city'
+    type: file
+    disableDeletion: false
+    updateIntervalSeconds: 30
+    allowUiUpdates: true
+    options:
+      path: /etc/grafana/provisioning/dashboards