feat(web): separate build sources and localize time

web/src/features/home/Home.tsx

@@ -99,10 +99,9 @@ export function Home() {
       </main>
 
       <aside className={styles.buildInfo} aria-label="构建信息">
-        <span>前端 v{buildInfo.frontendVersion}</span>
-        <span>tag {buildInfo.tag && buildInfo.tag !== 'unknown' ? buildInfo.tag : '未标记'}</span>
-        <span>commit {buildInfo.commit}</span>
-        <time dateTime={buildInfo.builtAt}>{buildInfo.builtAt} UTC</time>
+        <span>前端 v{buildInfo.frontendVersion} · tag {buildInfo.frontendTag || '未标记'} · commit {buildInfo.frontendCommit}</span>
+        <span>后端 tag {buildInfo.backendTag || '未标记'} · commit {buildInfo.backendCommit}</span>
+        <time dateTime={buildInfo.builtAt}>构建时间 {buildInfo.builtAtShanghai}</time>
       </aside>
 
       {createOpen ? <CreateSheet onClose={() => setCreateOpen(false)} onCreated={open} /> : null}