docs(gateway): gateway 剩余文件注释改中文（逐行 1:1，代码零字节改动）

主人 2026-10-03 拍板「注释一律中文」；gateway 至此整包注释中文化完成（本会话共 3 批：
已推库 16 个文件 + 本批剩余文件）。
校验：机械校验（非注释改动行）= 空；剥注释后代码文本逐行比对全等（不一致文件数 0）；
全树 go test ./... 58 包 ok / 0 FAIL；交叉编译绿。

internal/services/gateway/session_attribution_test.go

@@ -13,13 +13,13 @@ import (
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
 )
 
-// This file covers the end-to-end half of design/22 §7-5: a session that switched
-// roles must keep the conversation it had, and the model must be able to tell
-// which utterances came from the earlier role. The chain asserted here is:
-// chat_messages (per-message persona_id) → the orchestrator's seeded turn context
-// → the loop's speaker attribution → the model.Request the adapter receives.
+// 本文件覆盖 design/22 §7-5 的端到端一半：切换过角色的
+// 会话必须保留它曾有过的对话，且模型必须能分辨
+// 哪些话语来自更早的角色。这里断言的链条是：
+// chat_messages（每消息 persona_id）→ 编排器播种的回合上下文
+// → loop 的说话者归属 → 适配器收到的 model.Request。
 
-// requestTexts returns the text of every message of req, in order.
+// requestTexts 按顺序返回 req 每条消息的文本。
 func requestTexts(req model.Request) []string {
 	out := make([]string, 0, len(req.Messages))
 	for _, m := range req.Messages {
@@ -28,7 +28,7 @@ func requestTexts(req model.Request) []string {
 	return out
 }
 
-// messageTextOf concatenates the text parts of m.
+// messageTextOf 拼接 m 的文本部分。
 func messageTextOf(m model.Message) string {
 	var b strings.Builder
 	for _, c := range m.Content {
@@ -39,11 +39,11 @@ func messageTextOf(m model.Message) string {
 	return b.String()
 }
 
-// TestChatTurnCarriesSpeakerAttributionFromTranscript is design/22 §7-5 accepted
-// from the process boundary: the session already holds turns spoken by role X, it
-// is now bound to role Y, and one more chat turn arrives. The request must carry
-// X's earlier utterance with its speaker attributed to X (not to Y), keep every
-// stored body verbatim, and still open with Y's own instructions.
+// TestChatTurnCarriesSpeakerAttributionFromTranscript 是从进程边界验收的
+// design/22 §7-5：该会话已持有角色 X 说过的话，它现在
+// 绑定到角色 Y，且又来了一个聊天回合。请求必须携带
+// X 更早的话语且其说话者归属到 X（不是 Y），原样保留每个
+// 已存消息体，并仍以 Y 自己的指令开头。
 func TestChatTurnCarriesSpeakerAttributionFromTranscript(t *testing.T) {
 	t.Parallel()
 	ctx := context.Background()
@@ -53,8 +53,8 @@ func TestChatTurnCarriesSpeakerAttributionFromTranscript(t *testing.T) {
 	if err != nil {
 		t.Fatalf("NewSubSessionFor: %v", err)
 	}
-	// The conversation as it stood while the session spoke as X, with per-message
-	// persona ids exactly as the orchestrator persists them (design/22 §7-5).
+	// 该会话以 X 说话时的对话原貌，每消息
+	// persona id 与编排器持久化的完全一致（design/22 §7-5）。
 	for _, m := range []history.Message{
 		{SessionID: sub, Role: history.RoleUser, Content: "你还记得吗", PersonaID: "xilian", CreatedAt: 1000},
 		{SessionID: sub, Role: history.RoleAssistant, Content: "我记住了，你喜欢冰美式", PersonaID: "xilian", CreatedAt: 1001},
@@ -86,13 +86,13 @@ func TestChatTurnCarriesSpeakerAttributionFromTranscript(t *testing.T) {
 	}
 	req := ad.reqs[len(ad.reqs)-1]
 
-	// The answering role still owns the head of the prompt.
+	// 应答角色仍然占据提示词的开头。
 	if got := firstSystemText(req); got != "你是由纪。" {
 		t.Fatalf("first system = %q, want role Y's prompt", got)
 	}
 
-	// X's earlier utterance reached the model, verbatim (the turn is not amnesiac
-	// across the role switch).
+	// X 更早的话语原样抵达了模型（该回合没有
+	// 在角色切换处失忆）。
 	texts := requestTexts(req)
 	xIdx := -1
 	for i, txt := range texts {
@@ -111,7 +111,7 @@ func TestChatTurnCarriesSpeakerAttributionFromTranscript(t *testing.T) {
 		t.Fatalf("speaker label = %q, want xilian (the role that actually spoke it)", req.Messages[xIdx].SenderName)
 	}
 
-	// The speaker boundary names X and marks the stretch as not Y's own words.
+	// 说话者边界点明 X，并把那一段标记为不是 Y 自己的话。
 	note := ""
 	for _, m := range req.Messages {
 		if m.Role == model.RoleSystem && strings.Contains(messageTextOf(m), "「昔涟」（xilian）") {
@@ -123,8 +123,8 @@ func TestChatTurnCarriesSpeakerAttributionFromTranscript(t *testing.T) {
 		t.Fatalf("no speaker boundary for X found: %q", texts)
 	}
 
-	// No stored body was rewritten, and the newly sent user text carries no system
-	// metadata (the user lane stays free text, design/11 §10).
+	// 没有任何已存消息体被改写，且新发送的用户文本不携带 system
+	// 元数据（用户通道保持自由文本，design/11 §10）。
 	for _, m := range req.Messages {
 		if m.Role != model.RoleUser {
 			continue