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/list_after.go

@@ -5,15 +5,12 @@ import (
 	"fmt"
 )
 
-// ListAfter returns up to limit messages for sessionID strictly newer than after
-// (created_at > after) in oldest-first order, for forward incremental catch-up: a
-// client that reconnected passes the newest createdAt it has already seen and pulls
-// only what it missed, however many messages that is (the "before" cursor only walks
-// backwards and cannot recover a gap larger than one page). When platform is non-empty
-// the page is further restricted to messages carrying that source platform, exactly as
-// in List. rowid breaks created_at ties so messages written in the same millisecond
-// keep their insertion order. The returned slice is non-nil; limit is clamped to
-// [1, maxPageLimit].
+// ListAfter 按最旧优先返回 sessionID 中严格新于 after（created_at > after）的
+// 至多 limit 条消息，用于前向增量追赶：重连的客户端传入自己已见过的最新
+// createdAt，只拉取错过的部分，无论有多少条（"before" 游标只能向后走，无法
+// 恢复大于一页的空洞）。platform 非空时把该页进一步限制为携带该来源平台的
+// 消息，与 List 完全一致。rowid 打破 created_at 的并列，使同一毫秒写入的
+// 消息保持插入顺序。返回切片非 nil；limit 钳制到 [1, maxPageLimit]。
 func (s *Store) ListAfter(ctx context.Context, sessionID string, after int64, limit int, platform string) ([]Message, error) {
 	limit = clampLimit(limit)
 	query := `SELECT id, session_id, role, content, mode, mood, image, thinking, platform, device_id, sender_name, adapter_id, persona_id, created_at