docs(runtime): internal/runtime/loop 44 个文件注释改中文（逐行 1:1，代码零字节改动）

主人 2026-10-03 拍板「注释一律中文」；本模块按长期分批协议（一个模块一次派工）执行。
注释行数 1329 → 1329 逐行 1:1（含中文 33 → 1304）；行尾注释 5 条一并译。
校验：机械校验（非注释改动行）= 空；独立 Go AST 程序（剥注释复渲）证明 44/44 文件代码全等；
全树 go test ./... 58 包 ok / 0 FAIL；交叉编译绿。
gofmt：capacity_loop_test.go / flow.go 改动前即未格式化，按铁律保留原样未动。

internal/runtime/loop/stream.go

@@ -8,21 +8,21 @@ import (
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
 )
 
-// streamStep drives a streaming model call. It is the streaming counterpart of
-// agent.RunStep: it builds the request from the agent's public surface, runs the
-// loop's input guardrail, streams deltas through OnStream, runs the output
-// guardrail and decodes any tool calls. Because RunStep does not expose a stream
-// path, this method is owned by the loop; it mirrors the agent's semantics so the
-// two behave identically apart from the delta callback.
+// streamStep 驱动一次流式模型调用。它是
+// agent.RunStep 的流式对应物：它从 agent 的公开表面构建请求、
+// 运行循环的输入护栏、把增量流经 OnStream、运行输出
+// 护栏并解码所有工具调用。由于 RunStep 不暴露流式
+// 路径，该方法归循环所有；它镜像 agent 的语义，使两者
+// 除增量回调外行为一致。
 func (l *Loop) streamStep(ctx context.Context, messages []model.Message) (*stepOutcome, error) {
 	ag := l.agentFor(ctx)
 	adapter := ag.Adapter()
 	if adapter == nil {
 		return nil, fmt.Errorf("loop: stream step: %w", ErrNoAdapter)
 	}
-	// Resolve the role's agent and reasoning knobs once per step: the same pair is
-	// used for the request and for the per-delta broadcast gate, so a role switch
-	// can never apply the new prompt with the old broadcast switch mid-stream.
+	// 每个 step 解析一次该角色的 agent 与推理旋钮：同一对取值
+	// 既用于请求，也用于逐增量的广播门，因此角色切换
+	// 绝不会在流中途用旧的广播开关套用新的提示词。
 	knobs := l.knobsFor(ctx)
 	req := l.buildRequest(ctx, messages, ag, knobs)
 
@@ -37,17 +37,17 @@ func (l *Loop) streamStep(ctx context.Context, messages []model.Message) (*stepO
 	}
 
 	resp, err := adapter.ChatStream(ctx, req, func(ev model.StreamEvent) {
-		// Stamp the session/turn identity at the loop boundary: the adapter runs
-		// below the loop and cannot know which conversation the stream belongs to,
-		// so the loop fills it from the context it was driven with (design/16 §4.2)
-		// and the frontend can route the delta to the active session.
+		// 在循环边界打上 session/turn 身份：适配器运行在
+		// 循环之下，无法知道该流属于哪个会话，
+		// 因此循环用它被驱动的 context 填充（design/16 §4.2），
+		// 前端便能把增量路由到活跃会话。
 		ev.SessionID = loopSession(ctx)
 		ev.TurnID = loopTurn(ctx)
-		// Suppress UI broadcast for internal autonomous passes (backthink),
-		// whose intermediate reasoning must not leak into the chat stream, and for
-		// thinking frames when the turn's role turned them off (showToUser: false).
-		// Both gates are broadcast-only: the response the model produced is
-		// unchanged, so display and persistence stay decoupled.
+		// 为内部自主流程（backthink）抑制 UI 广播，
+		// 其中间推理不得泄露进聊天流；当该 turn 的角色
+		// 关闭思考帧时（showToUser: false）也抑制。两处门
+		// 都只影响广播：模型产出的响应
+		// 不变，因此展示与持久化保持解耦。
 		if l.onStream != nil && !isMutedBroadcast(ctx) && broadcasts(ev, knobs.ThinkingShowToUser) {
 			l.onStream(ev)
 		}
@@ -74,11 +74,11 @@ func (l *Loop) streamStep(ctx context.Context, messages []model.Message) (*stepO
 		modelStopReason: resp.StopReason, model: resp.Model}, nil
 }
 
-// broadcasts reports whether a streamed event may be pushed to the UI. Only
-// thinking frames are ever withheld, and only when the turn's role resolved
-// showToUser to false; text, tool-call and tool-progress frames are never
-// affected, so turning thinking off cannot change what the client sees of the
-// answer itself.
+// broadcasts 报告某流式事件是否可推给 UI。只有
+// 思考帧会被扣下，且仅当该 turn 的角色把
+// showToUser 解析为 false 时；文本、工具调用与工具进度帧
+// 从不受影响，因此关闭思考不会改变客户端所见
+// 的答案本身。
 func broadcasts(ev model.StreamEvent, showToUser *bool) bool {
 	if !isThinkingKind(ev.Kind) {
 		return true
@@ -86,7 +86,7 @@ func broadcasts(ev model.StreamEvent, showToUser *bool) bool {
 	return showToUser == nil || *showToUser
 }
 
-// isThinkingKind reports whether kind is one of the reasoning segment events.
+// isThinkingKind 报告 kind 是否为推理分段事件之一。
 func isThinkingKind(kind model.StreamKind) bool {
 	switch kind {
 	case model.StreamKindThinkingStart, model.StreamKindThinkingDelta, model.StreamKindThinkingEnd: