fix: WebSocket race conditions, Vue error handler, remove sudo podman, add container health checks

- F1: Guard connectWebSocket against concurrent calls with isWsConnecting flag
- F2: Serialize mesh send operations with sendQueue to prevent fetchMessages races
- F3: Add global Vue error handler with toast notification
- S1: Replace sudo podman with podman across all scripts (rootless Podman)
- S2: Add health-cmd to all 40 container run commands in first-boot-containers.sh

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

neode-ui/src/main.ts

@@ -4,6 +4,7 @@ import './style.css'
 import App from './App.vue'
 import router from './router'
 import i18n from './i18n'
+import { useToast } from '@/composables/useToast'
 
 const app = createApp(App)
 const pinia = createPinia()
@@ -12,4 +13,10 @@ app.use(pinia)
 app.use(router)
 app.use(i18n)
 
+app.config.errorHandler = (err, _instance, info) => {
+  console.error('[Vue Error]', err, info)
+  const { error } = useToast()
+  error('Something went wrong. Please refresh the page.')
+}
+
 app.mount('#app')