feat(api): support traffic bytes tracking in edge access logs and refactor analytics models

- Add `bytes_sent` to `NodeAccessLog` on both Agent and Master Server.
- Create ClickHouse migration `202607120001_add_bytes_sent_to_node_access_logs.sql`.
- Refactor duplicate stats structs by centralizing them into `analyticsmodel` package with type aliases.
- Simplify access log store delegations and remove redundant mapping loops.
- Regenerate Swagger documentation.
- Update changelog index.md.

internal/model/analytics/node_access_log.go

@@ -10,7 +10,7 @@ import (
 
 const (
 	nodeAccessLogTableName     = "of_node_access_logs"
-	nodeAccessLogInsertColumns = "id, node_id, logged_at, remote_addr, region, host, path, status_code, created_at"
+	nodeAccessLogInsertColumns = "id, node_id, logged_at, remote_addr, region, host, path, status_code, bytes_sent, created_at"
 )
 
 // NodeAccessLog stores OpenFlare edge node access records in ClickHouse.
@@ -23,6 +23,7 @@ type NodeAccessLog struct {
 	Host       string    `gorm:"column:host"`
 	Path       string    `gorm:"column:path"`
 	StatusCode int32     `gorm:"column:status_code"`
+	BytesSent  uint64    `gorm:"column:bytes_sent"`
 	CreatedAt  time.Time `gorm:"column:created_at"`
 }
 
@@ -39,4 +40,4 @@ func (NodeAccessLog) InsertColumns() string {
 // BatchInsertSQL returns the INSERT prefix used by native batch writers.
 func (NodeAccessLog) BatchInsertSQL() string {
 	return fmt.Sprintf("INSERT INTO %s (%s)", nodeAccessLogTableName, nodeAccessLogInsertColumns)
-}
+}