修复禅道Bug清单中的前端问题：好友申请source校验、群解散二次验证缺失、

群解散事件未处理、错误码翻译缺失、恢复登录页误导性提示

- 好友申请首次必失败30000（P0）：AddFriendModal把手机号搜索单独标记为
  source:"phone"上报，但后端serveIMFriendRequestCreate的source校验只认
  search/qr/group，命中default分支返回"invalid friend request source"。
  改为手机号搜索也统一上报source:"search"（后端本就不区分具体搜索渠道），
  用两个全新、此前无任何关系的测试账号验证首次申请200成功
- 解散群聊需要短信二次验证但完整流程从未实现（P0）：新增
  SecurityChallengeModal通用二次验证弹层（POST /security/challenges→
  验证码→verify→action_token）+ requestActionToken()（stores/
  securityChallenge.ts，与requestConfirm同一模式），接入解散群聊和转让
  群主（后者此前也因缺X-Action-Token必然404/400）。同时发现并修复
  imDelete对无body请求不显式传空对象体，导致携带Content-Type:
  application/json但请求体真正为空时后端JSON解码失败返回400——实测确认
  两个问题都解决后DELETE返回200
- 群聊被解散但当前正查看该群的用户界面不会跳转（P1）：新增
  topics.ts的subscribeTopicGone()监听SDK自身的onDeleteTopic回调，
  ConversationView据此在当前会话被解散时弹出提示并跳转回消息列表
- P2P会话发起方标题栏显示原始topic id、对方明明在线却显示离线：确认
  为上一轮已修复的isCommType()根因问题的同一症状，本轮实测（新建从未
  聊过天的账号对）已不再复现；群内消息发送者显示原始uid的关联描述同样
  实测未复现
- 好友关系冲突（已是好友/申请正在处理中）报错英文原文透出：翻译表补充
  FRIEND_REQUEST_CONFLICT
- 深链/刷新页面时的"改为重新登录"链接此前在任何恢复登录过程中都会
  立即显示（不管是否超时），造成短暂白屏时的误导性提示：改为仅在真正
  超时后才显示该链接，与其上方的提示文案保持一致的显示条件

web/src/App.tsx

@@ -6,6 +6,7 @@ import { ConfirmDialogRoot } from '@/app/ConfirmDialogRoot';
 import { GlobalToastRoot } from '@/app/GlobalToastRoot';
 import { KickedNoticeRoot } from '@/app/KickedNoticeRoot';
 import { RequireAuth } from '@/app/RequireAuth';
+import { SecurityChallengeModal } from '@/app/SecurityChallengeModal';
 import { EnterpriseRegisterPage } from '@/features/auth/EnterpriseRegisterPage';
 import { LoginPage } from '@/features/auth/LoginPage';
 import { ResetPasswordPage } from '@/features/auth/ResetPasswordPage';
@@ -106,6 +107,7 @@ export default function App() {
       <ConfirmDialogRoot />
       <GlobalToastRoot />
       <KickedNoticeRoot />
+      <SecurityChallengeModal />
     </QueryClientProvider>
   );
 }

web/src/app/RequireAuth.tsx

@@ -106,9 +106,17 @@ export function RequireAuth() {
     return (
       <div className="flex h-dvh flex-col items-center justify-center gap-3 bg-surface-page text-sm text-text-tertiary-3">
         {restoreTimedOut ? '连接时间较长，你可以继续等待，或改为重新登录' : '正在恢复登录状态…'}
-        <a href="/login" className="text-accent no-underline">
-          改为重新登录
-        </a>
+        {/* Only past the same timeout the message text itself waits for -- a normal restore usually
+            resolves in well under a second (real WS round trip), and this link showing unconditionally
+            from the very first frame made every ordinary reload/deep-link flash a "重新登录" escape
+            hatch that had nothing to escape from (a real, reported false-alarm: "短暂白屏并误显改为
+            重新登录"). The escape hatch is only actually useful once restoreTimedOut has already told
+            the user this is taking longer than normal. */}
+        {restoreTimedOut ? (
+          <a href="/login" className="text-accent no-underline">
+            改为重新登录
+          </a>
+        ) : null}
       </div>
     );
   }

web/src/app/SecurityChallengeModal.tsx

@@ -0,0 +1,144 @@
+import { useEffect, useRef, useState } from 'react';
+
+import { useEscapeKey } from '@/lib/hooks';
+import { ImApiError } from '@/lib/api/client';
+import { requestSecurityChallenge, verifySecurityChallenge } from '@/lib/api/security';
+import { useSecurityChallengeStore } from '@/stores/securityChallenge';
+
+/** Mounted once at the app root (App.tsx), same placement/pattern as ConfirmDialogRoot -- renders
+ *  whatever `requestActionToken()` (stores/securityChallenge.ts) most recently asked for: the
+ *  protocol's sensitive-action SMS re-verification (docs/IM-前后端对接文档.md:762-766), needed before
+ *  a group can actually be dissolved (or its ownership transferred) -- both require `X-Action-Token`,
+ *  and there was previously no UI anywhere in this app that could produce one. */
+export function SecurityChallengeModal() {
+  const pending = useSecurityChallengeStore((s) => s.pending);
+  const respond = useSecurityChallengeStore((s) => s.respond);
+  const [challengeId, setChallengeId] = useState('');
+  const [phoneMask, setPhoneMask] = useState('');
+  const [code, setCode] = useState('');
+  const [seconds, setSeconds] = useState(0);
+  const [busy, setBusy] = useState(false);
+  const [error, setError] = useState('');
+  const timerRef = useRef<number | undefined>(undefined);
+  useEscapeKey(() => respond(null));
+
+  const tick = (initial: number) => {
+    window.clearInterval(timerRef.current);
+    setSeconds(initial);
+    timerRef.current = window.setInterval(() => {
+      setSeconds((s) => {
+        if (s <= 1) {
+          window.clearInterval(timerRef.current);
+          return 0;
+        }
+        return s - 1;
+      });
+    }, 1000);
+  };
+
+  // Fires the first SMS the moment the modal opens -- the doc's own flow has no separate "get code"
+  // click for this endpoint (unlike VerificationCodeButton's register/reset-password scenes), since
+  // the phone number isn't something the user enters here at all (read server-side from the login
+  // identity), so there's nothing to wait on the user to fill in first.
+  useEffect(() => {
+    window.clearInterval(timerRef.current);
+    setChallengeId('');
+    setCode('');
+    setError('');
+    setSeconds(0);
+    if (!pending) return undefined;
+    let cancelled = false;
+    requestSecurityChallenge(pending.scene)
+      .then((data) => {
+        if (cancelled) return;
+        setChallengeId(data.challenge_id);
+        setPhoneMask(data.phone_mask);
+        tick(data.resend_after_seconds || 60);
+      })
+      .catch((err) => {
+        if (cancelled) return;
+        setError(err instanceof ImApiError ? err.message : '验证码发送失败，请重试');
+      });
+    return () => {
+      cancelled = true;
+      window.clearInterval(timerRef.current);
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [pending?.scene]);
+
+  if (!pending) return null;
+
+  const resend = () => {
+    if (busy || seconds > 0) return;
+    setError('');
+    setBusy(true);
+    requestSecurityChallenge(pending.scene)
+      .then((data) => {
+        setChallengeId(data.challenge_id);
+        setPhoneMask(data.phone_mask);
+        tick(data.resend_after_seconds || 60);
+      })
+      .catch((err) => setError(err instanceof ImApiError ? err.message : '验证码发送失败，请重试'))
+      .finally(() => setBusy(false));
+  };
+
+  const submit = async () => {
+    if (!challengeId || !/^\d{6}$/.test(code)) return setError('请输入 6 位验证码');
+    setBusy(true);
+    setError('');
+    try {
+      const verified = await verifySecurityChallenge(challengeId, code);
+      respond(verified.action_token);
+    } catch (err) {
+      setError(err instanceof ImApiError ? err.message : '验证码错误或已过期');
+      setBusy(false);
+    }
+  };
+
+  return (
+    <div className="fixed inset-0 z-[100] flex items-center justify-center bg-[#22262d]/25" onClick={() => respond(null)}>
+      <div className="w-[340px] rounded-xl bg-white p-5 shadow-modal" onClick={(e) => e.stopPropagation()}>
+        <strong className="mb-2 block text-base font-semibold text-text-heading">安全验证</strong>
+        <p className="m-0 text-sm leading-relaxed text-text-body">
+          即将{pending.actionDescription}，请验证手机号{phoneMask ? ` ${phoneMask}` : ''} 收到的短信验证码
+        </p>
+        <div className="mt-4 flex items-center gap-2">
+          <input
+            value={code}
+            onChange={(e) => setCode(e.target.value.replace(/\D/g, '').slice(0, 6))}
+            placeholder="请输入 6 位验证码"
+            inputMode="numeric"
+            autoFocus
+            className="h-9 min-w-0 flex-1 rounded-lg border border-border-panel px-3 text-sm outline-none focus:border-accent"
+          />
+          <button
+            type="button"
+            onClick={resend}
+            disabled={busy || seconds > 0 || !challengeId}
+            className="h-9 w-28 flex-none rounded-lg bg-accent-soft-bg text-sm text-accent disabled:bg-[#e6e9ee] disabled:text-text-tertiary-3"
+          >
+            {seconds > 0 ? `重新获取(${seconds}s)` : '重新获取'}
+          </button>
+        </div>
+        {error ? <p className="m-0 mt-2 text-xs text-danger-text">{error}</p> : null}
+        <div className="mt-5 flex justify-end gap-3">
+          <button
+            type="button"
+            onClick={() => respond(null)}
+            className="grid h-9 place-items-center rounded-lg border border-[#d5d9df] px-4 text-sm text-text-secondary"
+          >
+            取消
+          </button>
+          <button
+            type="button"
+            onClick={submit}
+            disabled={busy || !challengeId || code.length !== 6}
+            className="grid h-9 place-items-center rounded-lg bg-btn px-4 text-sm font-medium text-white disabled:opacity-50"
+          >
+            {busy ? '验证中…' : '确定'}
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}

web/src/features/contacts/AddFriendModal.tsx

@@ -47,7 +47,7 @@ export function AddFriendModal({ onClose, onSent, initialTarget }: AddFriendModa
   // Tracks HOW `selected` was populated so the eventual sendFriendRequest can report the real
   // provenance instead of always claiming "search" -- NewFriendsView's own SOURCE_LABEL map has a
   // dedicated "扫码添加" entry for the qr case that was otherwise dead/unreachable.
-  const [selectedSource, setSelectedSource] = useState<'search' | 'phone' | 'qr'>('search');
+  const [selectedSource, setSelectedSource] = useState<'search' | 'qr'>('search');
   const [message, setMessage] = useState('');
   const [error, setError] = useState('');
   const [sent, setSent] = useState(false);
@@ -227,12 +227,19 @@ export function AddFriendModal({ onClose, onSent, initialTarget }: AddFriendModa
                         type="button"
                         disabled={!selectable}
                         onClick={() => {
-                          // `searchType` (already computed above from the query itself) is the real
-                          // signal for which channel actually found this person -- NewFriendsView's
-                          // own SOURCE_LABEL table already has a `phone` entry ("通过手机号搜索")
-                          // that this path never reached because every search result was tagged
-                          // 'search' regardless of how it was found.
-                          setSelectedSource(searchType === 'phone' ? 'phone' : 'search');
+                          // Real, live-confirmed backend validation (im_http.go's
+                          // serveIMFriendRequestCreate): the `source` field's switch only recognizes
+                          // `search`/`qr`/`group` -- there is no `phone` case, so it falls to
+                          // `default` and 400s with "invalid friend request source". A prior pass
+                          // here tried to report phone-originated searches as their own `phone`
+                          // source (for NewFriendsView's SOURCE_LABEL table to show "通过手机号搜索"),
+                          // which broke every phone-search-based friend request outright -- reproduced
+                          // live with two brand-new accounts before this fix (first-ever request,
+                          // never a retry/idempotency issue as it first looked). Phone and account
+                          // search both go through the same `search` channel from the backend's own
+                          // point of view; there is no server-side data to recover that distinction
+                          // from, so `SOURCE_LABEL`'s dead `phone` entry is removed alongside this.
+                          setSelectedSource('search');
                           setSelected(item);
                         }}
                         className="flex items-center gap-3 rounded-lg px-2 py-2 text-left disabled:opacity-70"

web/src/features/contacts/NewFriendsView.tsx

@@ -11,7 +11,12 @@ import { acceptFriendRequest, getFriendRequests, rejectFriendRequest, type Frien
 import { avatarBgClass, avatarLetter } from '@/lib/avatar';
 import { formatEventTimestamp } from '@/lib/messages/time';
 
-const SOURCE_LABEL: Record<string, string> = { search: '通过账号搜索', qr: '扫码添加', group: '通过群聊添加', phone: '通过手机号搜索' };
+// `phone` deliberately excluded -- the backend's own `source` validation (im_http.go's
+// serveIMFriendRequestCreate) only accepts `search`/`qr`/`group`; a phone-number search reports the
+// same `search` value an account-name search does, since the server has no separate channel for it
+// (see AddFriendModal.tsx's own selection handler for the live-confirmed 400 this caused when it
+// tried to report `phone` as its own source instead).
+const SOURCE_LABEL: Record<string, string> = { search: '通过账号搜索', qr: '扫码添加', group: '通过群聊添加' };
 
 /** README §5.3: both pending (拒绝/通过验证 buttons) and already-handled (灰字"已通过/已拒绝")
  *  inbound requests show together in one list -- `getFriendRequests('inbound', 'all')` matches

web/src/features/groups/GroupAdminModal.tsx

@@ -24,6 +24,7 @@ import {
 import { avatarBgClass, avatarLetter } from '@/lib/avatar';
 import { useEscapeKey } from '@/lib/hooks';
 import { requestConfirm } from '@/stores/confirmDialog';
+import { requestActionToken } from '@/stores/securityChallenge';
 import { useSessionStore } from '@/stores/session';
 
 interface GroupAdminModalProps {
@@ -469,7 +470,8 @@ function TransferOwnerSubView({ topicId, groupVersion, onClose }: { topicId: str
   const queryClient = useQueryClient();
   const [error, setError] = useState('');
   const transferMutation = useMutation({
-    mutationFn: (userId: string) => transferGroupOwner(topicId, userId, groupVersion ?? 1),
+    mutationFn: ({ userId, actionToken }: { userId: string; actionToken: string }) =>
+      transferGroupOwner(topicId, userId, groupVersion ?? 1, actionToken),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ['group', topicId] });
       queryClient.invalidateQueries({ queryKey: ['group-settings', topicId] });
@@ -490,9 +492,10 @@ function TransferOwnerSubView({ topicId, groupVersion, onClose }: { topicId: str
         cacheKey="eligible-owner"
         opts={{ eligibleRole: 'owner' }}
         onPick={async (m) => {
-          if (await requestConfirm({ message: `确定将群主转让给 ${m.display_name || m.user_id} 吗？此操作不可撤销。`, danger: true })) {
-            transferMutation.mutate(m.user_id);
-          }
+          if (!(await requestConfirm({ message: `确定将群主转让给 ${m.display_name || m.user_id} 吗？此操作不可撤销。`, danger: true }))) return;
+          const actionToken = await requestActionToken({ scene: 'group_owner_transfer', actionDescription: '转让群主' });
+          if (!actionToken) return;
+          transferMutation.mutate({ userId: m.user_id, actionToken });
         }}
         emptyLabel="没有可转让的成员"
         disabled={transferMutation.isPending}

web/src/features/groups/GroupDetailColumn.tsx

@@ -28,6 +28,7 @@ import { avatarBgClass, avatarLetter } from '@/lib/avatar';
 import { useTinode } from '@/lib/tinode/hooks';
 import { requestConfirm } from '@/stores/confirmDialog';
 import { notify } from '@/stores/globalToast';
+import { requestActionToken } from '@/stores/securityChallenge';
 import { useSessionStore } from '@/stores/session';
 
 interface GroupDetailColumnProps {
@@ -157,7 +158,7 @@ export function GroupDetailColumn({ topicId, peerName, onClose, onOpenHistory }:
   });
 
   const disbandMutation = useMutation({
-    mutationFn: () => disbandGroup(topicId),
+    mutationFn: (actionToken: string) => disbandGroup(topicId, actionToken),
     onSuccess: () => navigate('/messages'),
     onError: (err) => showError(err, '解散群聊失败'),
   });
@@ -178,7 +179,12 @@ export function GroupDetailColumn({ topicId, peerName, onClose, onOpenHistory }:
   const startLeaveOrDisband = async () => {
     if (isOwner) {
       if (!(await requestConfirm({ message: '解散群聊后，所有成员将无法再查看和发送消息，此操作不可恢复。确定解散吗？', danger: true }))) return;
-      disbandMutation.mutate();
+      const actionToken = await requestActionToken({
+        scene: 'group_dissolve',
+        actionDescription: `解散群聊「${groupQuery.data?.name || peerName}」`,
+      });
+      if (!actionToken) return;
+      disbandMutation.mutate(actionToken);
     } else {
       if (!(await requestConfirm({ message: '确定退出本群聊吗？', danger: true }))) return;
       leaveMutation.mutate();

web/src/features/messages/ConversationView.tsx

@@ -29,10 +29,10 @@ import { buildMentionedContent, detectMentionTrigger, type PendingMention } from
 import { sendFile, sendImage, sendVoice } from '@/lib/tinode/attachments';
 import { useChatList, useTinode, useTopicMessages } from '@/lib/tinode/hooks';
 import { forwardMessage, sendPrebuiltContent, sendReply, sendText } from '@/lib/tinode/send';
-import { closeConversation, ensureTopicAttached, openConversation } from '@/lib/tinode/topics';
+import { closeConversation, ensureTopicAttached, openConversation, subscribeTopicGone } from '@/lib/tinode/topics';
 import { useCallStore } from '@/stores/calls';
 import { requestConfirm } from '@/stores/confirmDialog';
-import { notImplemented } from '@/stores/globalToast';
+import { notify, notImplemented } from '@/stores/globalToast';
 import { useMessageJumpStore } from '@/stores/messageJump';
 import { useSessionStore } from '@/stores/session';
 
@@ -165,6 +165,20 @@ export function ConversationView() {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [topicId]);
 
+  // Someone else dissolving the group currently open here (or this account being removed from it)
+  // fires the SDK's `onDeleteTopic`, not `onData`/`onPres` -- those only invalidate this screen's
+  // cached snapshots for re-render, they don't tell it the topic itself is gone. Left unhandled, the
+  // member who happened to be looking at that conversation just keeps staring at a now-defunct screen
+  // (an actual reported bug: staying on the dissolved group's view with no way back except a manual
+  // nav). `notify()` (the global toast, not this screen's own `errorToast`) survives the navigate.
+  useEffect(() => {
+    return subscribeTopicGone((goneTopicName) => {
+      if (goneTopicName !== topicId) return;
+      notify('该群聊已解散');
+      navigate('/messages', { replace: true });
+    });
+  }, [topicId, navigate]);
+
   // useLayoutEffect, not useEffect -- this component never remounts on topicId change (route is
   // `:topicId`), so a plain useEffect (which fires after paint) can let one frame render with the
   // PREVIOUS conversation's select-mode/menu/etc. still showing over the new conversation's message

web/src/lib/api/client.ts

@@ -87,6 +87,9 @@ const REASON_MESSAGES: Record<string, string | ((details: unknown) => string | n
   QR_CODE_EXPIRED: '二维码已过期，请对方刷新后重新扫描',
   QR_CODE_INVALID: '二维码无效，请重新扫描',
   FRIEND_REQUEST_NOT_ALLOWED: '对方暂不允许添加好友',
+  // `relation.Relationship != RelationshipNone` (im_http.go's serveIMFriendRequestCreate) -- already
+  // friends, or a request between the two of you (either direction) is already pending.
+  FRIEND_REQUEST_CONFLICT: '你们已经是好友，或好友申请正在处理中',
   USER_NOT_DISCOVERABLE: '未找到该用户',
   REQUEST_ALREADY_HANDLED: '该申请已被处理，请刷新查看最新状态',
   SEARCH_RATE_LIMITED: '搜索过于频繁，请稍后再试',

web/src/lib/api/groups.ts

@@ -130,9 +130,17 @@ export function leaveGroup(topic: string) {
   return imPost<{ topic: string; status: string }>(`/groups/${encodeURIComponent(topic)}/leave`, {});
 }
 
-/** doc-flagged 待实现 (not yet implemented server-side) -- kept typed and ready for when it lands. */
-export function disbandGroup(topic: string) {
-  return imDelete<{ topic: string; deleted: boolean }>(`/groups/${encodeURIComponent(topic)}`);
+/** Needs `X-Action-Token` (two-factor-guarded write, docs/IM-前后端对接文档.md §6.17) -- get one via
+ *  `requestActionToken({scene:'group_dissolve', ...})` (stores/securityChallenge.ts) first. Live,
+ *  fully implemented server-side (a stale comment here previously claimed otherwise) -- confirmed by
+ *  actually calling it. An explicit empty-object body is required: a bodiless DELETE still carries
+ *  this client's own `Content-Type: application/json` header, and the server's JSON decoder treats
+ *  a truly empty body under that header as malformed rather than "no optional fields provided". */
+export function disbandGroup(topic: string, actionToken: string) {
+  return imDelete<{ topic: string; deleted: boolean }>(`/groups/${encodeURIComponent(topic)}`, {
+    body: {},
+    headers: { 'X-Action-Token': actionToken },
+  });
 }
 
 export type GroupRole = 'owner' | 'admin' | 'member';
@@ -264,14 +272,14 @@ export function unmuteGroupMember(topic: string, userId: string) {
   return imDelete<{ user_id: string; muted: boolean }>(`/groups/${encodeURIComponent(topic)}/mutes/${encodeURIComponent(userId)}`);
 }
 
-/** Needs `X-Action-Token` (two-factor-guarded write, docs/IM-前后端对接文档.md §6.26) -- not yet
- *  wired since no risk-challenge flow is built anywhere in this app yet; calling this will 409 until
- *  that's added. Kept typed so the group-management UI can be built ahead of that. */
-export function transferGroupOwner(topic: string, targetUserId: string, version: number) {
-  return imPost<{ owner: string; previous_owner: string; version: number }>(`/groups/${encodeURIComponent(topic)}/owner-transfer`, {
-    target_user_id: targetUserId,
-    version,
-  });
+/** Needs `X-Action-Token` (two-factor-guarded write, docs/IM-前后端对接文档.md §6.26) -- get one via
+ *  `requestActionToken({scene:'group_owner_transfer', ...})` (stores/securityChallenge.ts) first. */
+export function transferGroupOwner(topic: string, targetUserId: string, version: number, actionToken: string) {
+  return imPost<{ owner: string; previous_owner: string; version: number }>(
+    `/groups/${encodeURIComponent(topic)}/owner-transfer`,
+    { target_user_id: targetUserId, version },
+    { headers: { 'X-Action-Token': actionToken } },
+  );
 }
 
 export function getGroupGovernance(topic: string) {

web/src/lib/api/security.ts

@@ -15,3 +15,27 @@ export interface UrlSafetyResult {
 export function checkUrlSafety(url: string, source: string) {
   return imPost<UrlSafetyResult>('/security/urls/check', { url, source });
 }
+
+/** Sensitive-action re-verification (docs/IM-前后端对接文档.md:762-766, §6.17's group-dissolve line).
+ *  Confirmed by reading im_be's own `validIMSecurityChallengeScene` (server/im_http.go) -- the doc
+ *  text only spells out the two youth-mode scenes by name, but the server also accepts
+ *  `group_dissolve`/`group_owner_transfer`, which is what actually lets this flow work for either. */
+export type SecurityChallengeScene = 'group_dissolve' | 'group_owner_transfer';
+
+export interface SecurityChallenge {
+  challenge_id: string;
+  phone_mask: string;
+  expires_in_seconds: number;
+  resend_after_seconds: number;
+}
+
+export function requestSecurityChallenge(scene: SecurityChallengeScene) {
+  return imPost<SecurityChallenge>('/security/challenges', { scene, channel: 'sms' });
+}
+
+export function verifySecurityChallenge(challengeId: string, code: string) {
+  return imPost<{ action_token: string; action: string; expires_at: string }>(
+    `/security/challenges/${encodeURIComponent(challengeId)}/verify`,
+    { code },
+  );
+}

web/src/lib/tinode/tinode-sdk.d.ts

@@ -257,6 +257,9 @@ declare module 'tinode-sdk' {
     onSubsUpdated?: (subs: string[], count?: number) => void;
     onPres?: (pres: unknown) => void;
     onAuxUpdated?: (aux: unknown) => void;
+    /** Fired by the SDK's own `Topic#_gone()` once this topic is confirmed deleted (group dissolved,
+     *  or this account removed from it) -- clears `public`/`private`/messages just before firing. */
+    onDeleteTopic?: () => void;
   }
 
   export class MeTopic extends Topic {

web/src/lib/tinode/topics.ts

@@ -64,6 +64,19 @@ export function subscribeTopicInfo(callback: (topicName: string, info: RawTopicI
   return () => infoListeners.delete(callback);
 }
 
+const goneListeners = new Set<(topicName: string) => void>();
+
+/** Fires once a topic is confirmed gone (group dissolved by anyone, or removed from this account) --
+ *  the SDK's own `Topic#_gone()` clears the topic's public/private/messages and calls
+ *  `onDeleteTopic()` (confirmed reading tinode.dev.js). Without ConversationView reacting to this,
+ *  a member who stays on a group's conversation screen while someone else dissolves it just keeps
+ *  looking at a now-defunct view -- `onMetaDesc`/`onPres`/etc. above only invalidate cached snapshots
+ *  for re-render, they don't tell the currently-open screen it needs to navigate away entirely. */
+export function subscribeTopicGone(callback: (topicName: string) => void): () => void {
+  goneListeners.add(callback);
+  return () => goneListeners.delete(callback);
+}
+
 function wireTopicCallbacks(topic: Topic) {
   if (wiredTopics.has(topic)) return;
   const notify = () => notifyTopic(topic.name);
@@ -86,6 +99,10 @@ function wireTopicCallbacks(topic: Topic) {
   topic.onPres = notify;
   topic.onAuxUpdated = notify;
   topic.onAllMessagesReceived = notify;
+  topic.onDeleteTopic = () => {
+    notify();
+    goneListeners.forEach((cb) => cb(topic.name));
+  };
   wiredTopics.add(topic);
 }
 

web/src/stores/securityChallenge.ts

@@ -0,0 +1,39 @@
+import { create } from 'zustand';
+
+import type { SecurityChallengeScene } from '@/lib/api/security';
+
+/**
+ * Prompts for the protocol's sensitive-action SMS re-verification (docs/IM-前后端对接文档.md:762-766)
+ * and resolves with the resulting `action_token`, or `null` if the user cancels -- same Promise
+ * shape/global-store-plus-single-root-component pattern as `confirmDialog.ts`'s `requestConfirm`, for
+ * the same reason: this needs to be callable from a mutation's `mutationFn` (GroupDetailColumn's
+ * dissolve flow, currently the only caller) with no natural "own a piece of JSX for this" home.
+ */
+export interface SecurityChallengeOptions {
+  scene: SecurityChallengeScene;
+  /** What's about to happen if the user completes verification -- e.g. "解散群聊「群名」". */
+  actionDescription: string;
+}
+
+interface PendingChallenge extends SecurityChallengeOptions {
+  resolve: (token: string | null) => void;
+}
+
+interface SecurityChallengeState {
+  pending: PendingChallenge | null;
+  respond: (token: string | null) => void;
+}
+
+export const useSecurityChallengeStore = create<SecurityChallengeState>((set, get) => ({
+  pending: null,
+  respond: (token) => {
+    get().pending?.resolve(token);
+    set({ pending: null });
+  },
+}));
+
+export function requestActionToken(options: SecurityChallengeOptions): Promise<string | null> {
+  return new Promise((resolve) => {
+    useSecurityChallengeStore.setState({ pending: { ...options, resolve } });
+  });
+}