fix(infra): disable spot nodes for ws deployment

WebSocket connections are long-lived and get disrupted by spot node
preemption. Moving ws pods to on-demand nodes for stability.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: capJavert

.infra/index.ts

@@ -425,7 +425,7 @@ if (isAdhocEnv) {
       livenessProbe,
       metric: { type: 'memory_cpu', cpu: 150, memory: 150 },
       disableLifecycle: true,
-      spot: { enabled: true },
+      spot: { enabled: false },
       podAnnotations: podAnnotations,
       ...vols,
     },