Initialize HemHub project foundation

frontend/src/App.tsx

@@ -0,0 +1,48 @@
+import { useEffect, useState } from 'react'
+
+type HealthResponse = {
+  status: string
+}
+
+function App() {
+  const [backendStatus, setBackendStatus] = useState<string | null>(null)
+  const [hasError, setHasError] = useState(false)
+
+  useEffect(() => {
+    const loadHealth = async () => {
+      try {
+        const response = await fetch('/api/health')
+
+        if (!response.ok) {
+          throw new Error(`Backend svarade med status ${response.status}`)
+        }
+
+        const health = (await response.json()) as HealthResponse
+        setBackendStatus(health.status)
+      } catch {
+        setHasError(true)
+      }
+    }
+
+    void loadHealth()
+  }, [])
+
+  let statusMessage = 'Kontrollerar backend…'
+
+  if (hasError) {
+    statusMessage = 'Backend kunde inte nås'
+  } else if (backendStatus) {
+    statusMessage = `Backend: ${backendStatus}`
+  }
+
+  return (
+    <main>
+      <h1>HemHub</h1>
+      <p>Frontend har startat.</p>
+      <p aria-live="polite">{statusMessage}</p>
+    </main>
+  )
+}
+
+export default App
+