Initial commit: SRDB - High-performance LSM-Tree database

- Core engine with MemTable, SST, WAL
- B+Tree indexing for SST files  
- Leveled compaction strategy
- Multi-table database management
- Schema validation and secondary indexes
- Query builder with complex conditions
- Web UI with HTMX for data visualization
- Command-line tools for diagnostics

manifest/manifest_writer.go

@@ -0,0 +1,35 @@
+package manifest
+
+import (
+	"io"
+	"sync"
+)
+
+// Writer MANIFEST 写入器
+type Writer struct {
+	file io.Writer
+	mu   sync.Mutex
+}
+
+// NewWriter 创建 MANIFEST 写入器
+func NewWriter(file io.Writer) *Writer {
+	return &Writer{
+		file: file,
+	}
+}
+
+// WriteEdit 写入版本变更
+func (w *Writer) WriteEdit(edit *VersionEdit) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	// 编码
+	data, err := edit.Encode()
+	if err != nil {
+		return err
+	}
+
+	// 写入
+	_, err = w.file.Write(data)
+	return err
+}