Update mavftp

ARCHITECTURE.md

@@ -101,6 +101,7 @@ Each sub-application has detailed architecture documentation covering requiremen
      - upload them to the flight controller,
      - save them to file
    - [`frontend_tkinter_parameter_editor.py`](ardupilot_methodic_configurator/frontend_tkinter_parameter_editor.py)
+     - [Flight-controller `.bin` log download architecture](ARCHITECTURE_download_bin_logs.md)
      - [External parameter file upload architecture](ARCHITECTURE_parameter_upload.md)
      - [`frontend_tkinter_parameter_editor_documentation_frame.py`](ardupilot_methodic_configurator/frontend_tkinter_parameter_editor_documentation_frame.py)
      - [`frontend_tkinter_parameter_editor_table.py`](ardupilot_methodic_configurator/frontend_tkinter_parameter_editor_table.py)

ARCHITECTURE_download_bin_logs.md

@@ -0,0 +1,184 @@
+# Flight-controller file browser
+
+**Status:** Implemented
+**Entry point:** Parameter Editor -> **Download .bin log file(s)**
+**Implemented on:** September 3, 2026
+
+## Purpose
+
+The Parameter Editor opens a modal, two-panel FTP-style browser for the
+connected flight controller. The remote MAVFTP panel is on the left and the
+local filesystem panel is on the right. The default remote location is
+`/APM/LOGS/`. The browser lists all valid regular remote files, not only
+numbered `.BIN` logs, and also displays directories. The existing
+**Download last .bin log file** workflow remains available.
+
+## User interface
+
+`DownloadBinLogsWindow` inherits from `BaseWindow`, is transient to the
+Parameter Editor, and uses a modal grab except on macOS.
+
+Each panel has a location entry, an icon-only `↖` parent-directory button,
+refresh/open controls, a Select all button, and a sortable `ttk.Treeview` with
+**Name**, **Type**, and **Size** columns.
+The remote entry is initialized to `/APM/LOGS/`; Enter in that field performs
+the same operation as Open/Refresh. Double-clicking a directory navigates into
+it. The local panel additionally provides Browse and Refresh controls.
+The local panel initially opens in the current Parameter Editor vehicle
+directory, falling back to the process working directory if that directory is
+unavailable.
+Backspace navigates to the parent directory of the panel that was most
+recently focused or had a selection change.
+Delete removes all selected files and empty directories in the last selected
+panel. F2 starts an inline rename for the last selected entry, with a name
+dialog fallback when inline editing is unavailable.
+
+Filename sorting is case-insensitive. Size sorting uses the numeric byte count,
+not the formatted display text. Treeview rows retain stable entry identifiers,
+so sorting does not change which file is selected. Ctrl+A and Command+A select
+all entries in the focused panel.
+
+## Operations
+
+The action bar provides:
+
+- **Download selected**: recursively copies selected remote files/directories
+  into the current local directory;
+- **Upload selected**: recursively copies selected local files/directories into
+  the current remote directory;
+- **Delete remote** and **Rename remote**;
+- **Delete local** and **Rename local**;
+- **Download last .bin log file**; and
+- **Cancel**.
+
+Rename requires exactly one selected entry and accepts only one safe path
+component. Parent navigation is performed only through the `↖` button or the
+Backspace shortcut; it is not represented as a selectable tree row.
+
+Remote downloads enumerate selected directories recursively, create the local
+directory tree, and download regular files. Local uploads create remote
+directories parent-first and upload regular files. Local symlinks are skipped.
+Deletion is deliberately non-recursive: remote and local directories must be
+empty. A non-empty directory is reported as failed while other selected files
+and empty directories continue to be processed.
+
+Batch operations continue after individual transfer or management failures.
+The modal reports succeeded and failed paths separately after each operation.
+
+## Layered architecture
+
+```text
+ParameterEditorWindow
+        |
+        v
+DownloadBinLogsWindow(BaseWindow)
+        |  injected dialogs/messages/ProgressWindow
+        v
+ParameterEditor
+        |
+        v
+FlightController
+        |
+        v
+FlightControllerFiles
+        |
+        v
+MAVFTP
+```
+
+The Tkinter window owns modal lifecycle, panel navigation, selection, sorting,
+local enumeration, recursive operation planning, dialogs, confirmations,
+progress updates, and summaries. It does not call MAVFTP directly.
+
+`ParameterEditor` delegates these operations:
+
+```python
+get_bin_log_files(remote_directory)
+get_remote_files(remote_directory)
+upload_file_to_fc(local_filename, remote_filename, progress_callback)
+download_remote_file(remote_path, local_filename, progress_callback)
+make_remote_directory(remote_directory)
+delete_remote_path(remote_path, is_directory=False)
+rename_remote_path(remote_path, new_remote_path)
+download_selected_bin_logs_workflow(...)
+download_last_flight_log_workflow(...)
+```
+
+`DownloadBinLogsUiServices` injects save-file, directory, and rename selectors,
+confirmation/message callbacks, and the standard application ProgressWindow
+factory. The legacy single/multiple regular-file download workflow is retained:
+one file uses a save-file selector, multiple files use a directory selector,
+and existing targets receive one overwrite confirmation.
+
+## Backend model and MAVFTP
+
+`FlightControllerFiles.list_remote_files()` returns files and directories;
+`list_bin_log_files()` retains its historical name and filters that listing to
+regular files. The manager also implements explicit upload/download, directory
+creation, deletion, and rename operations, while retaining the existing
+LASTLOG/fallback last-log workflow.
+
+```python
+@dataclass(frozen=True)
+class FlightControllerLogFile:
+    name: str
+    remote_path: str
+    size_bytes: int
+    is_directory: bool = False
+```
+
+The local panel uses an equivalent `LocalFileEntry` containing `name`, `path`,
+`size_bytes`, and `is_directory`.
+
+Remote paths are normalized to absolute POSIX paths and parent segments are
+rejected. Directory entry names must be a single component without `/` or
+`\\`; embedded, leading, and trailing spaces are preserved, and malformed
+listing names are skipped. Paths are passed to MAVFTP as argument values, not
+through a shell, so filenames do not need quoting. This prevents malformed
+MAVFTP entries from escaping the selected directory during recursive
+operations.
+
+The current MAVFTP `DirectoryEntry` exposes `name`, `is_dir`, and `size_b`, but
+no modification timestamp. Therefore modification dates cannot currently be
+displayed; that requires MAVFTP and firmware support for timestamp metadata.
+
+## Progress and error behavior
+
+Remote transfers run in a worker thread so the Tk event loop remains responsive.
+The browser uses the standard ProgressWindow and adapts each MAVFTP percentage
+callback into aggregate byte-oriented batch progress. The Cancel button signals
+the active transfer to stop at the next MAVFTP progress boundary and failed
+transfers terminate their MAVFTP session. Zero-byte files count as one progress
+unit. Empty directories are created without file progress units.
+
+Missing local destinations and invalid remote paths are reported before work
+starts. Existing local download targets prompt once. Upload confirmation is
+conservative because the browser does not pre-query every remote target.
+Later entries continue after a transfer failure. Local symlinks are never
+included in recursive transfer or destructive operations.
+
+Known limitations are that listing errors and empty directories both appear as
+an empty listing, recursive directory planning can briefly block the UI,
+explicit remote methods do not use capability-based directory scoping, and
+there is no modification-date metadata. Mutations outside `/APM/LOGS/` display
+an additional warning and require a separate confirmation.
+
+## Testing
+
+`tests/test_download_bin_logs.py` covers generic listing and directory metadata,
+MAVFTP management delegation, recursive planning and execution for downloads
+and uploads, recursive deletion, rename, batch continuation after failure,
+filename and numeric-size sorting, Select all/Ctrl+A, parent-directory button
+and Backspace navigation, remote refresh/Enter behavior, legacy destination
+selectors, and modal integration.
+
+```text
+.venv\Scripts\python.exe -m pytest tests/test_download_bin_logs.py -q -p no:cacheprovider
+```
+
+## Deferred hardening
+
+- modification-date display pending MAVFTP metadata support;
+- structured listing errors instead of an empty-list error channel;
+- preflight upload conflict discovery; and
+- real-Tk/end-to-end MAVFTP integration tests.

ardupilot_methodic_configurator/backend_flightcontroller.py

@@ -32,7 +32,7 @@
     SUPPORTED_BAUDRATES,
     FlightControllerConnection,
 )
-from ardupilot_methodic_configurator.backend_flightcontroller_files import FlightControllerFiles
+from ardupilot_methodic_configurator.backend_flightcontroller_files import FlightControllerFiles, FlightControllerLogFile
 from ardupilot_methodic_configurator.backend_flightcontroller_params import FlightControllerParams
 from ardupilot_methodic_configurator.backend_flightcontroller_protocols import (
     FlightControllerCommandsProtocol,
@@ -585,6 +585,44 @@ def download_last_flight_log(
         """Download the last flight log from the flight controller - delegates to files manager."""
         return self._files_manager.download_last_flight_log(local_filename, progress_callback)
 
+    def list_bin_log_files(self, remote_directory: str = "/APM/LOGS/") -> list[FlightControllerLogFile]:
+        """List regular files in a remote directory - delegates to files manager."""
+        return self._files_manager.list_bin_log_files(remote_directory)
+
+    def list_remote_files(self, remote_directory: str = "/APM/LOGS/") -> list[FlightControllerLogFile]:
+        """List files and directories in a remote directory - delegates to files manager."""
+        return self._files_manager.list_remote_files(remote_directory)
+
+    def download_bin_log_file(
+        self,
+        remote_path: str,
+        local_filename: str,
+        progress_callback: Callable[[int, int], None] | None = None,
+    ) -> bool:
+        """Download an explicitly selected remote file - delegates to files manager."""
+        return self._files_manager.download_bin_log_file(remote_path, local_filename, progress_callback)
+
+    def download_remote_file(
+        self,
+        remote_path: str,
+        local_filename: str,
+        progress_callback: Callable[[int, int], None] | None = None,
+    ) -> bool:
+        """Download one remote file - delegates to files manager."""
+        return self._files_manager.download_remote_file(remote_path, local_filename, progress_callback)
+
+    def make_remote_directory(self, remote_directory: str) -> bool:
+        """Create a remote directory - delegates to files manager."""
+        return self._files_manager.make_remote_directory(remote_directory)
+
+    def delete_remote_path(self, remote_path: str, is_directory: bool = False) -> bool:
+        """Delete a remote file or directory - delegates to files manager."""
+        return self._files_manager.delete_remote_path(remote_path, is_directory)
+
+    def rename_remote_path(self, remote_path: str, new_remote_path: str) -> bool:
+        """Rename a remote file or directory - delegates to files manager."""
+        return self._files_manager.rename_remote_path(remote_path, new_remote_path)
+
     # Static methods and properties
 
     @staticmethod