feat: add employee management, backend health check, and UI improvements

web/src/composables/useBackendHealth.js

@@ -0,0 +1,47 @@
+import { ref } from 'vue'
+
+import { fetchBackendHealth } from '../services/system.js'
+
+const backendHealthy = ref(true)
+const backendChecking = ref(false)
+const backendError = ref('')
+let lastCheckedAt = 0
+
+export async function checkBackendHealth(options = {}) {
+  const force = Boolean(options.force)
+  const now = Date.now()
+
+  if (!force && now - lastCheckedAt < 5000) {
+    return backendHealthy.value
+  }
+
+  backendChecking.value = true
+
+  try {
+    const payload = await fetchBackendHealth()
+    const ok = payload?.status === 'ok'
+
+    backendHealthy.value = ok
+    backendError.value = ok
+      ? ''
+      : payload?.database?.error || '后端服务尚未准备完成。'
+    lastCheckedAt = now
+    return ok
+  } catch (error) {
+    backendHealthy.value = false
+    backendError.value = error?.message || '无法连接后端服务。'
+    lastCheckedAt = now
+    return false
+  } finally {
+    backendChecking.value = false
+  }
+}
+
+export function useBackendHealth() {
+  return {
+    backendHealthy,
+    backendChecking,
+    backendError,
+    checkBackendHealth
+  }
+}