docs(comments): 注释中文化 · internal/runtime/history（15 文件，纯替换）

- 只翻注释/文档字符串：剥离注释后代码行逐字节不变（机械校验只剩 4 条行尾注释的翻译，代码前缀全等）
- 交叉引用（design/16 §4.6、D4/B3、0010 迁移文件名）逐字保留
- 保留未译技术词：DDL/rowid/LIKE/LEFT JOIN/DTO/rune/WS/actor 及全部标识符与表名
- 顺带副作用：store.go、session_persona_test.go 由注释文字改变而变得 gofmt 干净（未运行 gofmt -w）

internal/runtime/history/session_persona_test.go

@@ -6,8 +6,7 @@ import (
 	"testing"
 )
 
-// personaOf returns the stored role binding of a session, failing the test when the
-// session is absent from the list.
+// personaOf 返回某个会话已存储的角色绑定，会话不在列表中时使测试失败。
 func personaOf(t *testing.T, st *Store, id string) string {
 	t.Helper()
 	sessions, err := st.ListSessions(context.Background())
@@ -23,11 +22,10 @@ func personaOf(t *testing.T, st *Store, id string) string {
 	return ""
 }
 
-// TestSessionPersonaRoundTrip is design/22 acceptance 1: the session-level role is
-// the single source of truth, so a value written through SetSessionPersona must come
-// back from both the direct read and the list projection (the DTO the client gets),
-// and the main session — which always exists — starts out unbound ('' = inherit the
-// global default). An explicit "" clears the binding back to that same state.
+// TestSessionPersonaRoundTrip 是 design/22 验收 1：会话级角色是唯一事实来源，
+// 因此通过 SetSessionPersona 写入的值必须能从直接读取与列表投影（客户端拿到的
+// DTO）两条路径读回，而始终存在的主会话初始为未绑定（空 = 继承全局默认）。
+// 显式空串会把绑定清回同一状态。
 func TestSessionPersonaRoundTrip(t *testing.T) {
 	t.Parallel()
 	st := newStore(t)
@@ -52,8 +50,7 @@ func TestSessionPersonaRoundTrip(t *testing.T) {
 		}
 	}
 
-	// An explicit empty value is the documented "unbind" (follow the default again),
-	// not a no-op.
+	// 显式空值是文档化的「解绑」（重新跟随默认），不是空操作。
 	if err := st.SetSessionPersona(ctx, MainSessionID, ""); err != nil {
 		t.Fatalf("SetSessionPersona(\"\"): %v", err)
 	}
@@ -62,9 +59,9 @@ func TestSessionPersonaRoundTrip(t *testing.T) {
 	}
 }
 
-// TestSessionPersonaUnknownSession covers the error contract: binding or reading the
-// role of a session that does not exist reports ErrSessionNotFound (so the HTTP layer
-// answers 404) instead of silently creating/looking up nothing.
+// TestSessionPersonaUnknownSession 覆盖错误契约：绑定或读取一个不存在的会话的
+// 角色会报 ErrSessionNotFound（因此 HTTP 层回答 404），而不是悄悄创建/查不到
+// 任何东西。
 func TestSessionPersonaUnknownSession(t *testing.T) {
 	t.Parallel()
 	st := newStore(t)
@@ -78,10 +75,9 @@ func TestSessionPersonaUnknownSession(t *testing.T) {
 	}
 }
 
-// TestNewSubSessionForBindsPersona locks the create path: a sub session created with a
-// role carries it from its first read (no extra PATCH needed), and the plain
-// NewSubSession still creates an unbound session — the pre-multi-character contract,
-// which every existing caller relies on.
+// TestNewSubSessionForBindsPersona 锁定创建路径：带角色创建的子会话从第一次读取
+// 起就携带它（无需额外 PATCH），而朴素的 NewSubSession 仍创建未绑定会话 —— 即
+// 多角色之前的契约，每个既有调用方都依赖它。
 func TestNewSubSessionForBindsPersona(t *testing.T) {
 	t.Parallel()
 	st := newStore(t)
@@ -104,11 +100,10 @@ func TestNewSubSessionForBindsPersona(t *testing.T) {
 	}
 }
 
-// TestMessagePersonaPersisted proves design/22 §7-5's storage half: a session may
-// switch roles while keeping its context, so every message records the role that
-// SPOKE it. The column survives the write/read round trip through the same scanner
-// the REST/WS DTOs use, and messages written without a role stay '' (= the default
-// role), which is what keeps pre-upgrade history readable.
+// TestMessagePersonaPersisted 证明 design/22 §7-5 的存储一半：一个会话可以在保留
+// 上下文的同时切换角色，因此每条消息都记录说出它的那个角色。该列通过 REST/WS
+// DTO 使用的同一个扫描器活过写入/读取往返，而未指定角色写入的消息保持为空
+// （= 默认角色），这正是升级前历史仍可读的原因。
 func TestMessagePersonaPersisted(t *testing.T) {
 	t.Parallel()
 	st := newStore(t)
@@ -139,8 +134,8 @@ func TestMessagePersonaPersisted(t *testing.T) {
 		t.Fatalf("unattributed message persona_id = %q, want ''", got)
 	}
 
-	// The persona column must also survive Recent (the WS replay path) and
-	// AppendFull (the orchestrator's realtime-sync path).
+	// persona 列还必须活过 Recent（WS 回放路径）与 AppendFull（编排器的实时
+	// 同步路径）。
 	recent, err := st.Recent(ctx, MainSessionID, 10)
 	if err != nil {
 		t.Fatalf("recent: %v", err)