fix(web): code review round 1 remaining UI fixes

- EmojiPanel: add missing 手势/物品 categories, 12-column grid per README §3.3
- DetailColumn: add 投诉举报 row, real ID/region/签名 via new getUserProfile
  API, chevron_right icons now use --color-icon-arrow token (were tertiary
  text color), regroup rows so dividers only sit between sections not every
  row (matches design-code reference exactly)
- MessageBubble/ConversationView: right-clicked message bubble now gets the
  spec's outline while its context menu is open
- ChatListColumn/AppShell: pinned 系统消息/文件助手 rows using confirmed
  bootstrap entries/entry_badges topic names ("sys"/"slf"); route to the
  existing SectionPlaceholder pattern since their own dedicated layouts are
  Phase 8, not built yet

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/lib/api/friends.ts

@@ -72,6 +72,25 @@ export function rejectFriendRequest(requestId: string, version?: number) {
   return imPost<void>(`/friend-requests/${encodeURIComponent(requestId)}/reject`, version !== undefined ? { version } : {});
 }
 
+export interface UserProfile {
+  user_id: string;
+  display_name: string;
+  remark?: string;
+  avatar_file_id?: string;
+  gender?: string;
+  region?: string;
+  public_account?: string;
+  signature?: string;
+  relationship: string;
+  topic?: string;
+}
+
+/** `identifier` accepts `user_id`, `username`, or `public_account` -- P2P topic names are the peer's
+ *  own user_id (Tinode convention), so DetailColumn can pass `topicId` straight through. */
+export function getUserProfile(identifier: string) {
+  return imGet<UserProfile>(`/users/${encodeURIComponent(identifier)}/profile`);
+}
+
 export interface ConversationSettings {
   pinned: boolean;
   mute_notifications: boolean;