feat: embed k3s in neuron-web image to run soul-demo as managed pods

soul-demo now runs as a k3s Deployment with HPA (1–8 replicas, 60% CPU
target) instead of a bare background process. k3s starts first in
entrypoint.sh, imports the soul-demo:local OCI tar from
/var/lib/rancher/k3s/agent/images, and auto-applies the Deployment,
NodePort Service, and HPA from the server/manifests dir. neuron-web
starts only after the soul-demo pod is Running. Cloud Run gen2 execution
environment required for k3s (provides /dev/kmsg and Linux capabilities).

.gitea/workflows/deploy.yaml

@@ -211,6 +211,7 @@ jobs:
             --image "$IMAGE" \
             --region us-central1 \
             --project neuron-785695 \
+            --execution-environment gen2 \
             --service-account neuron-marketing-sa@neuron-785695.iam.gserviceaccount.com \
             --update-env-vars "NODE_ENV=production,STRIPE_PUBLISHABLE_KEY=pk_test_51TPoHnJg9Fv1D3AUp1FEMcy4MGlKRZqs4scW66kjQFQjWofmNc2rottzXzDaXekHvuw1OQpyp2WCIsc7O5fXIG0G00HQQrkdGX,GCS_SHARE_BUCKET=neuron-shares-prod,SUPABASE_ANON_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZSIsInJlZiI6Im9jb2pzZ2hhb25sdHVuaWRrenB3Iiwicm9sZSI6ImFub24iLCJpYXQiOjE3Nzc2NDIxNjgsImV4cCI6MjA5MzIxODE2OH0.e0FVFw1aahnrBVvnkR5R8a-RxCx095U8o_gsk7Quq3E,NEURON_LLM_0_FORMAT=anthropic,NEURON_LLM_0_MODEL=claude-sonnet-4-5,NEURON_LLM_0_URL=https://api.anthropic.com/v1/messages" \
             --update-secrets "SUPABASE_SERVICE_KEY=supabase-service-key:latest,NEURON_LLM_0_KEY=anthropic-api-key:latest,ANTHROPIC_API_KEY=anthropic-api-key:latest,STRIPE_SECRET_KEY=stripe-secret-key-stage:latest,STRIPE_WEBHOOK_SECRET=stripe-webhook-secret-stage:latest,STRIPE_PRICE_PROFESSIONAL=stripe-price-professional-stage:latest,STRIPE_PRICE_FOUNDING=stripe-price-founding-stage:latest,STRIPE_PRICE_FAMILY_CHILD=stripe-price-family-child:latest,RESEND_API_KEY=resend-api-key:latest,DOCUSEAL_WEBHOOK_TOKEN=docuseal-webhook-token:latest" \
@@ -228,6 +229,7 @@ jobs:
 
           gcloud run services update marketing-stage \
             --region us-central1 --project neuron-785695 \
+            --execution-environment gen2 \
             --update-env-vars "NEURON_ORIGIN=${STAGE_URL}" \
             --quiet
 
@@ -265,6 +267,7 @@ jobs:
               --image "$IMAGE" \
               --region "$region" \
               --project neuron-785695 \
+              --execution-environment gen2 \
               --quiet
           }
           deploy us-central1     marketing-prod-us   &