fix(neuron-mcp): blue/green deployment, memory limits, preStop drain hook

- Rename Deployment to neuron-mcp-blue with slot=blue label
- Add neuron-mcp-green Deployment scaffold (replicas=0, ready to receive new image)
- Service selector now routes by slot label; annotation tracks active slot
- Memory: 768Mi → 1536Mi limit, 256Mi → 512Mi request (fixes OOM pod restarts / 502s)
- Add JAVA_TOOL_OPTIONS: container-aware GC + ExitOnOutOfMemoryError
- Add preStop sleep 8s so Traefik drains in-flight connections before pod terminates
- terminationGracePeriodSeconds: 30
- Add scripts/blue-green-deploy.sh: automated slot-swap with health check and rollback

servers/legion/k8s/neuron-technologies/prod/services.yaml

@@ -21,9 +21,14 @@ metadata:
   namespace: neuron-prod
   labels:
     app: neuron-mcp
+  annotations:
+    # Blue/green: change slot to "green" then back to "blue" to switch traffic.
+    # Process: deploy green → verify health → patch this selector → scale blue to 0.
+    neuron.ai/active-slot: "blue"
 spec:
   selector:
     app: neuron-mcp
+    slot: blue
   ports:
     - name: http
       port: 8080