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/desktop/pages/file_manager_page.dart

@@ -282,11 +282,9 @@ class _FileManagerPageState extends State<FileManagerPage>
                                     item.state != JobState.inProgress,
                                 child: LinearPercentIndicator(
                                   animateFromLastPercent: true,
-                                  center: Text(
-                                    '${(item.finishedSize / item.totalSize * 100).toStringAsFixed(0)}%',
-                                  ),
+                                  center: Text(item.percentText),
                                   barRadius: Radius.circular(15),
-                                  percent: item.finishedSize / item.totalSize,
+                                  percent: item.percent,
                                   progressColor: MyTheme.accent,
                                   backgroundColor: Theme.of(context).hoverColor,
                                   lineHeight: kDesktopFileTransferRowHeight,