Fix autoupdate, add healtcheck status to the dashboard

ui/src/composables/index.ts

@@ -2,3 +2,4 @@ export { useSSE } from './useSSE'
 export { useStats } from './useStats'
 export { useTimeline } from './useTimeline'
 export { useUpdate } from './useUpdate'
+export { useHealth } from './useHealth'

ui/src/composables/useHealth.ts

@@ -0,0 +1,55 @@
+import { ref, onMounted, onUnmounted } from 'vue'
+import type { SelfCheckResponse } from '@/types'
+
+const CHECK_INTERVAL = 30 * 1000 // 30 seconds
+
+export function useHealth() {
+  const health = ref<SelfCheckResponse | null>(null)
+  const loading = ref(false)
+  const error = ref<string | null>(null)
+  let intervalId: ReturnType<typeof setInterval> | null = null
+
+  async function fetchHealth() {
+    loading.value = true
+    error.value = null
+    try {
+      const response = await fetch('/api/selfcheck')
+      if (!response.ok) {
+        throw new Error(`HTTP ${response.status}`)
+      }
+      health.value = await response.json()
+    } catch (e) {
+      error.value = e instanceof Error ? e.message : 'Unknown error'
+      health.value = null
+    } finally {
+      loading.value = false
+    }
+  }
+
+  function startPolling() {
+    fetchHealth()
+    intervalId = setInterval(fetchHealth, CHECK_INTERVAL)
+  }
+
+  function stopPolling() {
+    if (intervalId) {
+      clearInterval(intervalId)
+      intervalId = null
+    }
+  }
+
+  onMounted(() => {
+    startPolling()
+  })
+
+  onUnmounted(() => {
+    stopPolling()
+  })
+
+  return {
+    health,
+    loading,
+    error,
+    refresh: fetchHealth
+  }
+}