feat(web): show ban actor and timestamp in chat info

docs/core-checklist-status.md

@@ -31,7 +31,7 @@ Legend:
 22. Text Formatting - `PARTIAL` (bold/italic/underline/spoiler/mono/links + strikethrough + quote/code block; toolbar still evolving)
 23. Groups - `PARTIAL` (create/add/remove/invite link; join-by-invite and invite permissions covered by integration tests; members API now returns profile fields (`username/name/avatar_url`) and web Chat Info consumes them to avoid extra per-member profile requests; add-member search also shows avatars; advanced moderation still partial)
 24. Roles - `DONE` (owner/admin/member)
-25. Admin Rights - `PARTIAL` (delete/pin/edit info + explicit ban APIs for groups/channels including ban list endpoint; web Chat Info now shows searchable `Banned users` with both inline and right-click `Unban` actions for owner/admin, member search, avatars in moderation lists, and invite-link copy/regenerate actions; integration tests cover channel member read-only, channel admin full-delete, channel message delete-for-all permissions, group profile edit permissions, owner-only role management rules, and admin-visible/member-forbidden ban-list access; remaining UX moderation tools limited)
+25. Admin Rights - `PARTIAL` (delete/pin/edit info + explicit ban APIs for groups/channels including ban list endpoint; web Chat Info now shows searchable `Banned users` with both inline and right-click `Unban` actions for owner/admin, member search, avatars in moderation lists, invite-link copy/regenerate actions, and ban metadata (`who banned/when`); integration tests cover channel member read-only, channel admin full-delete, channel message delete-for-all permissions, group profile edit permissions, owner-only role management rules, and admin-visible/member-forbidden ban-list access; remaining UX moderation tools limited)
 26. Channels - `PARTIAL` (create/post/edit/delete/subscribe/unsubscribe; integration tests now also cover invite-link permissions (member forbidden, admin allowed); UX edge-cases still polishing)
 27. Channel Types - `DONE` (public/private)
 28. Notifications - `PARTIAL` (browser notifications + mute/settings; chat mute is propagated in chat list payload, honored by web realtime notifications with mention override, and mute toggle now syncs instantly in chat store; backend now emits `chat_updated` after notification mute/unmute for cross-tab consistency; no mobile push infra)

web/src/components/ChatInfoPanel.tsx

@@ -168,7 +168,7 @@ export function ChatInfoPanel({ chatId, open, onClose }: Props) {
     try {
       const nextBans = await listChatBans(targetChatId);
       setBans(nextBans);
-      const ids = [...new Set(nextBans.map((item) => item.user_id))];
+      const ids = [...new Set(nextBans.flatMap((item) => [item.user_id, item.banned_by_user_id]))];
       const profiles = await Promise.all(ids.map((id) => getUserById(id)));
       const byId: Record<number, AuthUser> = {};
       for (const profile of profiles) {
@@ -712,6 +712,9 @@ export function ChatInfoPanel({ chatId, open, onClose }: Props) {
                           <div className="min-w-0">
                             <p className="truncate text-xs font-semibold text-slate-200">{user?.name || `user #${ban.user_id}`}</p>
                             <p className="truncate text-[11px] text-slate-400">@{user?.username || "unknown"}</p>
+                            <p className="truncate text-[10px] text-slate-500">
+                              by @{bannedUsers[ban.banned_by_user_id]?.username || `user${ban.banned_by_user_id}`} • {new Date(ban.created_at).toLocaleString()}
+                            </p>
                             <p className="truncate text-[10px] text-slate-500">Right click for actions</p>
                           </div>
                         </div>