重构：简化查询接口

- RecordQuery.QueryOldest 和 QueryNewest 不再接收 startIdx/endIdx 参数
- 查询方法返回纯 Record 列表，状态判断移到调用方
- TopicProcessor 的查询方法负责添加状态信息
- 更新所有测试文件以适配新接口

seqlog_test.go

@@ -1211,7 +1211,6 @@ func TestRecordQuery(t *testing.T) {
 	writer.Close()
 
 	// 模拟处理到第 5 条记录
-	currentPos := offsets[5]
 	// 窗口范围：[索引 5, 索引 6)
 	startIdx := 5
 	endIdx := 6
@@ -1231,41 +1230,45 @@ func TestRecordQuery(t *testing.T) {
 	defer query.Close()
 
 	// 测试查询当前位置
-	current, err := query.QueryAt(currentPos, 0, 1, startIdx, endIdx)
+	current, err := query.QueryOldest(startIdx, 1)
 	if err != nil {
 		t.Fatalf("failed to query current: %v", err)
 	}
 	if len(current) != 1 {
 		t.Fatalf("expected 1 current result, got %d", len(current))
 	}
-	if string(current[0].Record.Data) != "message 5" {
-		t.Errorf("expected current 'message 5', got '%s'", string(current[0].Record.Data))
+	if string(current[0].Data) != "message 5" {
+		t.Errorf("expected current 'message 5', got '%s'", string(current[0].Data))
 	}
-	if current[0].Status != StatusProcessing {
-		t.Errorf("expected status Processing, got %s", current[0].Status)
+	// 手动判断状态
+	status := GetRecordStatus(startIdx, startIdx, endIdx)
+	if status != StatusProcessing {
+		t.Errorf("expected status Processing, got %s", status)
 	}
 
-	// 测试向后查询（查询更早的记录）
-	backResults, err := query.QueryAt(currentPos, -1, 3, startIdx, endIdx)
+	// 测试向后查询（查询更早的记录，返回倒序）
+	backResults, err := query.QueryNewest(startIdx-1, 3)
 	if err != nil {
 		t.Fatalf("failed to query backward: %v", err)
 	}
 	if len(backResults) != 3 {
 		t.Errorf("expected 3 backward results, got %d", len(backResults))
 	}
-	// 向后查询返回顺序结果
-	expectedBack := []string{"message 2", "message 3", "message 4"}
+	// 向后查询返回倒序结果（newest first）
+	expectedBack := []string{"message 4", "message 3", "message 2"}
 	for i, rec := range backResults {
-		if string(rec.Record.Data) != expectedBack[i] {
-			t.Errorf("backward[%d]: expected '%s', got '%s'", i, expectedBack[i], string(rec.Record.Data))
+		if string(rec.Data) != expectedBack[i] {
+			t.Errorf("backward[%d]: expected '%s', got '%s'", i, expectedBack[i], string(rec.Data))
 		}
-		if rec.Status != StatusProcessed {
-			t.Errorf("backward[%d]: expected status Processed, got %s", i, rec.Status)
+		// 手动判断状态：索引 4, 3, 2
+		recStatus := GetRecordStatus(startIdx-1-i, startIdx, endIdx)
+		if recStatus != StatusProcessed {
+			t.Errorf("backward[%d]: expected status Processed, got %s", i, recStatus)
 		}
 	}
 
 	// 测试向前查询（查询更新的记录）
-	forwardResults, err := query.QueryAt(currentPos, 1, 3, startIdx, endIdx)
+	forwardResults, err := query.QueryOldest(endIdx, 3)
 	if err != nil {
 		t.Fatalf("failed to query forward: %v", err)
 	}
@@ -1275,11 +1278,13 @@ func TestRecordQuery(t *testing.T) {
 	// 向前查询返回顺序结果
 	expectedForward := []string{"message 6", "message 7", "message 8"}
 	for i, rec := range forwardResults {
-		if string(rec.Record.Data) != expectedForward[i] {
-			t.Errorf("forward[%d]: expected '%s', got '%s'", i, expectedForward[i], string(rec.Record.Data))
+		if string(rec.Data) != expectedForward[i] {
+			t.Errorf("forward[%d]: expected '%s', got '%s'", i, expectedForward[i], string(rec.Data))
 		}
-		if rec.Status != StatusPending {
-			t.Errorf("forward[%d]: expected status Pending, got %s", i, rec.Status)
+		// 手动判断状态：索引 6, 7, 8
+		recStatus := GetRecordStatus(endIdx+i, startIdx, endIdx)
+		if recStatus != StatusPending {
+			t.Errorf("forward[%d]: expected status Pending, got %s", i, recStatus)
 		}
 	}
 
@@ -1329,14 +1334,9 @@ func TestTopicQuery(t *testing.T) {
 	endIdx := processor.GetReadIndex()
 	t.Logf("Processing index: [%d, %d)", startIdx, endIdx)
 
-	// 获取共享查询器
-	query := processor.Query()
-	index := processor.Index()
-
-	// 测试查询当前位置
+	// 测试查询当前位置（使用 processor 方法，带状态）
 	if startIdx < endIdx {
-		startPos, _ := index.GetOffset(startIdx)
-		current, err := query.QueryAt(startPos, 0, 1, startIdx, endIdx)
+		current, err := processor.QueryOldest(startIdx, 1)
 		if err != nil {
 			t.Fatalf("failed to query current: %v", err)
 		}
@@ -1347,8 +1347,7 @@ func TestTopicQuery(t *testing.T) {
 
 	// 测试向后查询
 	if startIdx > 0 {
-		startPos, _ := index.GetOffset(startIdx)
-		back, err := query.QueryAt(startPos, -1, 2, startIdx, endIdx)
+		back, err := processor.QueryNewest(startIdx-1, 2)
 		if err != nil {
 			t.Fatalf("failed to query backward: %v", err)
 		}
@@ -1358,9 +1357,8 @@ func TestTopicQuery(t *testing.T) {
 	}
 
 	// 测试向前查询
-	if startIdx < index.Count() {
-		startPos, _ := index.GetOffset(startIdx)
-		forward, err := query.QueryAt(startPos, 1, 3, startIdx, endIdx)
+	if startIdx < processor.GetRecordCount() {
+		forward, err := processor.QueryOldest(endIdx, 3)
 		if err != nil {
 			t.Fatalf("failed to query forward: %v", err)
 		}
@@ -1414,14 +1412,13 @@ func TestSeqlogQuery(t *testing.T) {
 	endIdx := seq.GetReadIndex("app")
 	t.Logf("Processing index: [%d, %d)", startIdx, endIdx)
 
-	// 获取 index 用于转换索引到 offset
+	// 获取 processor 用于查询（带状态）
 	processor, _ := seq.GetProcessor("app")
 	index := processor.Index()
 
 	// 测试查询当前
 	if startIdx < endIdx {
-		startPos, _ := index.GetOffset(startIdx)
-		current, err := query.QueryAt(startPos, 0, 1, startIdx, endIdx)
+		current, err := processor.QueryOldest(startIdx, 1)
 		if err != nil {
 			t.Fatalf("failed to query current: %v", err)
 		}
@@ -1432,8 +1429,7 @@ func TestSeqlogQuery(t *testing.T) {
 
 	// 测试向后查询
 	if startIdx > 0 {
-		startPos, _ := index.GetOffset(startIdx)
-		back, err := query.QueryAt(startPos, -1, 2, startIdx, endIdx)
+		back, err := processor.QueryNewest(startIdx-1, 2)
 		if err != nil {
 			t.Fatalf("failed to query backward: %v", err)
 		}
@@ -1444,8 +1440,7 @@ func TestSeqlogQuery(t *testing.T) {
 
 	// 测试向前查询
 	if startIdx < index.Count() {
-		startPos, _ := index.GetOffset(startIdx)
-		forward, err := query.QueryAt(startPos, 1, 3, startIdx, endIdx)
+		forward, err := processor.QueryOldest(endIdx, 3)
 		if err != nil {
 			t.Fatalf("failed to query forward: %v", err)
 		}