feat(driver): add sjtu netdisk driver (#9572)

Add SJTU Netdisk (pan.sjtu.edu.cn) driver with full file operations:
- List files with pagination support
- Download via S3 presigned URL with X-Amz-Expires TTL parsing
- Upload with three-step S3 presigned flow
- Create directory, rename, move (with conflict merge), copy, delete
- Token auto-refresh with expiration caching and fallback

Driver registered in drivers/all.go via init() side-effect import.

Author: dkf0321

drivers/all.go

@@ -69,6 +69,7 @@ import (
 	_ "github.com/alist-org/alist/v3/drivers/s3"
 	_ "github.com/alist-org/alist/v3/drivers/seafile"
 	_ "github.com/alist-org/alist/v3/drivers/sftp"
+	_ "github.com/alist-org/alist/v3/drivers/sjtu_netdisk"
 	_ "github.com/alist-org/alist/v3/drivers/smb"
 	_ "github.com/alist-org/alist/v3/drivers/streamtape"
 	_ "github.com/alist-org/alist/v3/drivers/strm"