Add site banner, build number, and changelog

frontend/app/changelog/page.tsx

@@ -0,0 +1,85 @@
+'use client'
+
+import { useEffect, useMemo, useState } from 'react'
+import { useRouter } from 'next/navigation'
+import { authFetch, clearToken, getApiBase, getToken } from '../lib/auth'
+
+type SiteInfo = {
+  changelog?: string
+}
+
+const parseChangelog = (raw: string) =>
+  raw
+    .split('\n')
+    .map((line) => line.trim())
+    .filter(Boolean)
+
+export default function ChangelogPage() {
+  const router = useRouter()
+  const [entries, setEntries] = useState<string[]>([])
+  const [loading, setLoading] = useState(true)
+
+  useEffect(() => {
+    const token = getToken()
+    if (!token) {
+      router.push('/login')
+      return
+    }
+    let active = true
+    const load = async () => {
+      try {
+        const baseUrl = getApiBase()
+        const response = await authFetch(`${baseUrl}/site/info`)
+        if (!response.ok) {
+          if (response.status === 401) {
+            clearToken()
+            router.push('/login')
+            return
+          }
+          throw new Error('Failed to load changelog')
+        }
+        const data: SiteInfo = await response.json()
+        if (!active) return
+        setEntries(parseChangelog(data?.changelog ?? ''))
+      } catch (err) {
+        console.error(err)
+        if (!active) return
+        setEntries([])
+      } finally {
+        if (active) setLoading(false)
+      }
+    }
+    void load()
+    return () => {
+      active = false
+    }
+  }, [router])
+
+  const content = useMemo(() => {
+    if (loading) {
+      return <div className="loading-text">Loading changelog...</div>
+    }
+    if (entries.length === 0) {
+      return <div className="meta">No updates posted yet.</div>
+    }
+    return (
+      <ul className="changelog-list">
+        {entries.map((entry, index) => (
+          <li key={`${entry}-${index}`}>{entry}</li>
+        ))}
+      </ul>
+    )
+  }, [entries, loading])
+
+  return (
+    <div className="page">
+      <section className="card changelog-card">
+        <div className="changelog-header">
+          <h1>Changelog</h1>
+          <p className="lede">Latest updates and release notes.</p>
+        </div>
+        {content}
+      </section>
+    </div>
+  )
+}