feat: display app version in sidebar with GitHub release check

frontend/src/hooks/useLatestRelease.ts

@@ -0,0 +1,42 @@
+import { useEffect, useState } from 'react'
+
+interface ReleaseInfo {
+  version: string
+  url: string
+}
+
+let cache: ReleaseInfo | null | 'error' | 'pending' = null
+
+export function useLatestRelease(currentVersion: string) {
+  const [latest, setLatest] = useState<ReleaseInfo | null>(
+    cache && cache !== 'error' && cache !== 'pending' ? cache : null,
+  )
+
+  useEffect(() => {
+    if (cache !== null) return
+    cache = 'pending'
+    fetch('https://api.github.com/repos/Pouzor/homelable/releases/latest', {
+      headers: { Accept: 'application/vnd.github+json' },
+    })
+      .then((res) => {
+        if (!res.ok) { cache = 'error'; return }
+        return res.json()
+      })
+      .then((data) => {
+        if (!data || typeof data.tag_name !== 'string' || !data.html_url) {
+          cache = 'error'
+          return
+        }
+        const version = data.tag_name.replace(/^v/, '')
+        const info: ReleaseInfo = { version, url: data.html_url }
+        cache = info
+        setLatest(info)
+      })
+      .catch(() => {
+        cache = 'error'
+      })
+  }, [])
+
+  const hasUpdate = latest !== null && latest.version !== currentVersion
+  return { latest, hasUpdate }
+}