feat(gateway+web): D 消息编辑/删除 WS 实时广播 — message_edited/message_deleted

- 后端: ws_hub.go broadcastMessageEdited(完整DTO,thinking剥离)/broadcastMessageDeleted(全广播+sessionId,前端过滤); history_write.go PATCH/DELETE成功后触发(404/400/501不广播); history/message_ops.go GetMessage(导出壳,取删除前sessionId)
- 前端: useAppStore.updateMessageById/removeMessageById + messageEventApplies(同会话过滤); ws.ts 消费两事件(缺content丢弃); dispatchFrame导出(可测)
- 真机e2e: PATCH/DELETE → WS收到 message_edited/message_deleted, 二次删404无帧
- Docs/api-client v0.34 §3.8; 测试 history_write_broadcast_test + messageSync.test(14 checks)
- 遗留: 前端编辑/删除UI入口+api客户端函数未接(lib/api 无 PATCH/DELETE messages); ws_hub.go 589行>500(既有)

frontend/web/src/store/useAppStore.ts

@@ -73,6 +73,13 @@ export interface AppStore {
    *  it also adopts a same-role local optimistic bubble (rewriting its uid to the
    *  backend id) so a message never renders twice (design/16 §4.3 dedup). */
   appendOrUpdateMessage: (msg: ChatMessage) => void;
+  /** Patch one already-rendered message in place by id — the `message_edited` WS
+   *  path. A no-op when the id is not in the active session, so an edit broadcast
+   *  for another conversation can never inject a row here. */
+  updateMessageById: (id: string, patch: Partial<ChatMessage>) => void;
+  /** Drop one message by id — the `message_deleted` WS path. A no-op when the id
+   *  is absent (another session's message, or a duplicate frame). */
+  removeMessageById: (id: string) => void;
 
   addUserMessage: (text: string, mode?: Mode, image?: string, deviceId?: string) => void;
   beginAssistant: (mode?: Mode, deviceId?: string) => string;
@@ -192,6 +199,21 @@ export const useAppStore = create<AppStore>()(
           return { messages: [...s.messages, msg] };
         }),
 
+      updateMessageById: (id, patch) =>
+        set((s) => {
+          const idx = s.messages.findIndex((m) => m.id === id);
+          if (idx === -1) return s;
+          const messages = s.messages.slice();
+          messages[idx] = { ...messages[idx], ...patch };
+          return { messages };
+        }),
+
+      removeMessageById: (id) =>
+        set((s) => {
+          const messages = s.messages.filter((m) => m.id !== id);
+          return messages.length === s.messages.length ? s : { messages };
+        }),
+
       addUserMessage: (text, mode, image, deviceId) =>
         set((s) => ({
           messages: [
@@ -383,3 +405,20 @@ export function lastStreamingMessage(s: AppStore): ChatMessage | undefined {
   const last = s.messages[s.messages.length - 1];
   return last?.role === "assistant" ? last : undefined;
 }
+
+/** Does an edit/delete frame scoped to `sessionId` belong to the conversation the
+ *  UI is showing? `message_edited` / `message_deleted` carry the owning session so
+ *  the rule matches `message_persisted`: only the active session's messages are
+ *  rendered, so another conversation's frame must not touch this list.
+ *
+ *  A frame without a session id is id-scoped (the backend could not resolve the
+ *  conversation — see the gateway's optional message lookup). It still applies:
+ *  message ids are globally unique, so the by-id update/removal can only ever match
+ *  a message of its own session, and an id we do not hold is a no-op either way. */
+export function messageEventApplies(
+  sessionId: string | undefined,
+  activeSessionId: string
+): boolean {
+  if (!sessionId) return true;
+  return sessionId === activeSessionId;
+}