docs(gateway): WS 帧门相关 11 个文件的注释改中文（只改注释，代码零字节改动）

主人 2026-10-03 拍板「注释一律中文」。本次先把本会话动过的文件就地翻；
不做全仓一次性翻译，存量按包分批排期（见 工作小结.md 待办）。

范围：ws_frame_scope.go / ws_frame_scope_test.go / broadcast.go / ws_hub_turn.go /
ws_hub_message_event.go / session_read.go / server.go / ws_hub_stream_scope_test.go /
history_write_broadcast_test.go / mood_test.go / extra_test.go
含中文的整行注释 18 → 382。

校验（判据 = "只改注释、零代码字节改动"）：
- `git diff -U0 | 排除 +++/--- | 排除注释行/空行/行尾注释` → 为空
- 独立实现：两侧剥掉注释后逐行比对代码文本 → 11/11 文件全等，不一致数 0
- 行尾注释 7 行逐条列出，代码列与原文逐字节相同（gofmt 未要求重排）
- gofmt -l 干净；全树 go build/vet 绿；go test ./... = 58 包 ok / 0 FAIL；
  linux/amd64 + darwin/arm64 交叉编译绿
语义未删减：部分折行英文长句合并为更少行，故整行注释数 438 → 399。

internal/services/gateway/ws_hub_message_event.go

@@ -1,31 +1,30 @@
 package gateway
 
-// 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 fan-out as `message_persisted` — and,
-// like it and every other content frame, they are owner/admin only under the
-// design/11 §7.1 frame gate. 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.
+// wsMessageEdited / wsMessageDeleted 是 D3 历史写入的下行事件类型：
+// 消息内容被编辑，或消息被删除。二者复用 wsEvent 信封与
+// `message_persisted` 相同的扇出 —— 并且与它以及其他所有内容帧
+// 一样，在 design/11 §7.1 帧门下只发 owner/admin。hub 没有按会话的
+// 订阅，因此帧携带 SessionID，由客户端按其活跃会话过滤，与它对
+// message_persisted 的处理完全一致。
 const (
 	wsMessageEdited  = "message_edited"
 	wsMessageDeleted = "message_deleted"
 )
 
-// broadcastMessageEdited fans a content edit out to the owner/admin connections 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.
+// broadcastMessageEdited 把一次内容编辑作为 `message_edited` 帧扇出到
+// owner/admin 连接，其 data 是更新后的消息 DTO。该帧只用于渲染同步：
+// 编辑后内容的唯一事实来源仍是 history store，因此错过该帧的客户端
+// 会在下次读取时重新收敛。调用方会抹除 Thinking，以匹配
+// message_persisted/回放契约。
 func (h *hub) broadcastMessageEdited(msg historyMessage) {
 	h.broadcast(wsEvent{Type: wsMessageEdited, SessionID: msg.SessionID, Data: msg})
 }
 
-// broadcastMessageDeleted fans a removal out to the owner/admin connections 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.
+// broadcastMessageDeleted 把一次删除作为 `message_deleted` 帧扇出到
+// owner/admin 连接，携带被删除的 id（外加所属 sessionId，供客户端
+// 按会话过滤），使该账号的每个浏览器无需刷新即可移除该行。
+// 当存储无法报告 sessionID 时它可能为空；客户端此时回退到全局
+// 唯一的 id。
 func (h *hub) broadcastMessageDeleted(sessionID, id string) {
 	h.broadcast(wsEvent{Type: wsMessageDeleted, SessionID: sessionID, Data: map[string]any{"id": id}})
 }