feat(web): add account workspaces and signed content flows

web/src/features/home/InvitationInbox.tsx

@@ -15,9 +15,11 @@ export function InvitationInbox() {
     catch (cause) { setError(cause instanceof Error ? cause.message : '加入失败'); }
     finally { setBusy(undefined); }
   }
-  return <div><strong>空间邀请</strong>
-    <Button variant="ghost" disabled={Boolean(busy)} onClick={() => { void accountApi.invitations().then(setInvitations).catch(() => setError('读取邀请失败')); }}>刷新邀请</Button>
-    {invitations.length === 0 ? <p className={styles.note}>暂无邀请。</p> : invitations.map((row) => <div className={styles.actions} key={row.channel_id}>
+  return <div>
+    <div className={styles.sectionHeader}><strong>空间邀请</strong>
+      <Button variant="ghost" disabled={Boolean(busy)} onClick={() => { void accountApi.invitations().then(setInvitations).catch(() => setError('读取邀请失败')); }}>刷新</Button>
+    </div>
+    {invitations.length === 0 ? <p className={styles.note}>暂无邀请。</p> : invitations.map((row) => <div className={styles.invitationRow} key={row.channel_id}>
       <span>空间 {row.channel_id.slice(0, 8)}…</span><Button disabled={Boolean(busy)} onClick={() => { void accept(row.channel_id); }}>{busy === row.channel_id ? '加入中…' : '接受邀请'}</Button>
     </div>)}
     {error ? <p className={styles.error} role="alert">{error}</p> : null}