fix: persist service host port; demo-data scope for telemetry

Public URLs were ephemeral: every restart/redeploy rebound a random host
port, so endpoint links rotted. Persist published_port on the service and
prefer it for replica 0 on create. If the port is taken, fall back to
ephemeral and repersist the new assignment. Post-start the binding is
verified — Docker Desktop accepts a conflicting publish silently, which
previously left services running with no endpoint at all.

demo-data.ts gains the required scope field for HostMonitoring (CI fix).

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

app/backend/internal/api/deployments.go

@@ -356,6 +356,12 @@ func runDeploymentAndSyncWithImage(
 		replicas = 1
 	}
 
+	var publishedPort int32
+	// Best effort: reuse the host port from the last live deployment so public
+	// URLs survive redeploys. Column exists post-migration; older DBs get
+	// ephemeral ports.
+	_ = db.QueryRow(`SELECT published_port FROM services WHERE id = $1`, service.ID).Scan(&publishedPort)
+
 	deployReq := &deployment.DeploymentRequest{
 		ProjectID:   service.ProjectID.String(),
 		ServiceID:   service.ID.String(),
@@ -367,6 +373,7 @@ func runDeploymentAndSyncWithImage(
 			Environment:   env,
 			Replicas:      replicas,
 			PublicPort:    int32(service.Port),
+			PublishedPort: publishedPort,
 			Domain:        service.Domain,
 			HealthPath:    service.HealthCheckPath,
 			RestartPolicy: service.RestartPolicy,