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)

internal/services/gateway/ws_hub.go

@@ -188,6 +188,35 @@ func (h *hub) broadcast(ev wsEvent) {
 	}
 }
 
+// wsMessageEdited / wsMessageDeleted are the downstream event types of the D3
+// history writes: a message's content was edited, or a message was removed. Both
+// reuse the wsEvent envelope and the same all-connections fan-out as
+// `message_persisted` — the hub has no per-session subscription, so the frame
+// carries SessionID and a client filters it by its active session, exactly as it
+// does for message_persisted.
+const (
+	wsMessageEdited  = "message_edited"
+	wsMessageDeleted = "message_deleted"
+)
+
+// broadcastMessageEdited fans a content edit out to every client as a
+// `message_edited` frame whose data is the updated message DTO. The frame is a
+// render-only sync: the edited content's single source of truth stays the history
+// store, so a client that missed the frame converges again on its next read. The
+// caller strips Thinking to match the message_persisted/replay contract.
+func (h *hub) broadcastMessageEdited(msg historyMessage) {
+	h.broadcast(wsEvent{Type: wsMessageEdited, SessionID: msg.SessionID, Data: msg})
+}
+
+// broadcastMessageDeleted fans a removal out to every client as a
+// `message_deleted` frame carrying the removed id (plus the owning sessionId for
+// client-side session filtering), so every browser of the account drops the row
+// without a refresh. sessionID may be empty when the store could not report it;
+// clients then fall back to the globally unique id.
+func (h *hub) broadcastMessageDeleted(sessionID, id string) {
+	h.broadcast(wsEvent{Type: wsMessageDeleted, SessionID: sessionID, Data: map[string]any{"id": id}})
+}
+
 // relay is the bus handler for the ws.> pattern and the producer bridge
 // patterns. The ws.chat subject is a streaming trigger (run the loop and emit
 // chunks); a ws.* subject becomes an outbound event of its design type; a