feat(fs): delegate win --server file reading to CM (#13736)

- Route Windows server-to-client file reads through CM instead of the connection layer
- Add FS IPC commands (ReadFile, CancelRead, SendConfirmForRead, ReadAllFiles) and CM data messages
  (ReadJobInitResult, FileBlockFromCM, FileReadDone, FileReadError, FileDigestFromCM, AllFilesResult)
- Track pending read validations and read jobs to coordinate CM-driven file transfers and clean them up
  on completion, cancellation, and errors
- Enforce a configurable file-transfer-max-files limit for ReadAllFiles and add stronger file name/path
  validation on the CM side
- Improve Flutter file transfer UX and robustness:
  - Use explicit percent/percentText progress fields
  - Derive speed and cancel actions from the active job
  - Handle job errors via FileModel.handleJobError and complete pending recursive tasks on failure
  - Wrap recursive directory operations in try/catch and await sendRemoveEmptyDir when removing empty directories

Signed-off-by: fufesou <linlong1266@gmail.com>

flutter/lib/models/cm_file_model.dart

@@ -275,7 +275,7 @@ class TransferJobSerdeData {
       : this(
           connId: d['connId'] ?? 0,
           id: int.tryParse(d['id'].toString()) ?? 0,
-          path: d['path'] ?? '',
+          path: d['dataSource'] ?? '',
           isRemote: d['isRemote'] ?? false,
           totalSize: d['totalSize'] ?? 0,
           finishedSize: d['finishedSize'] ?? 0,