feat(lasuite): add calendars service deployment manifests

Add K8s manifests for calendars backend, frontend (Caddy), CalDAV
server, and Celery worker. Wire Pingora routing for cal.sunbeam.pt
with path-based backend/caldav/static splits. Add OAuth2Client for
OIDC, VaultDynamicSecret for DB credentials, VaultStaticSecret for
Django/CalDAV keys, and TLS cert coverage for the cal subdomain.
Register calendars in the integration service gaufre widget.

base/lasuite/calendars-frontend-service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: calendars-frontend
+  namespace: lasuite
+spec:
+  selector:
+    app: calendars-frontend
+  ports:
+    - port: 80
+      targetPort: 8080