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/stores/mesh.ts

@@ -118,6 +118,9 @@ export const useMeshStore = defineStore('mesh', () => {
   const error = ref<string | null>(null)
   const sending = ref(false)
 
+  // Serialize send operations to prevent concurrent fetchMessages() races
+  let sendQueue: Promise<void> = Promise.resolve()
+
   // Node position tracking for map view (contact_id -> position)
   const nodePositions = ref<Map<number, NodePosition>>(new Map())
 
@@ -247,24 +250,30 @@ export const useMeshStore = defineStore('mesh', () => {
   }
 
   async function sendMessage(contactId: number, message: string) {
-    try {
-      sending.value = true
-      error.value = null
-      const res = await rpcClient.call<{ sent: boolean; message_id: number; encrypted: boolean }>({
-        method: 'mesh.send',
-        params: { contact_id: contactId, message: message.trim() },
-      })
-      // Refresh messages after sending
-      if (res.sent) {
-        await fetchMessages()
+    const doSend = async () => {
+      try {
+        sending.value = true
+        error.value = null
+        const res = await rpcClient.call<{ sent: boolean; message_id: number; encrypted: boolean }>({
+          method: 'mesh.send',
+          params: { contact_id: contactId, message: message.trim() },
+        })
+        // Refresh messages after sending
+        if (res.sent) {
+          await fetchMessages()
+        }
+        return res
+      } catch (err: unknown) {
+        error.value = err instanceof Error ? err.message : 'Failed to send mesh message'
+        throw err
+      } finally {
+        sending.value = false
       }
-      return res
-    } catch (err: unknown) {
-      error.value = err instanceof Error ? err.message : 'Failed to send mesh message'
-      throw err
-    } finally {
-      sending.value = false
     }
+    // Chain onto send queue to prevent concurrent fetchMessages() calls
+    const result = sendQueue.then(doSend, doSend)
+    sendQueue = result.then(() => {}, () => {})
+    return result
   }
 
   async function broadcastIdentity() {