Keep the import progress popup quiet while Hot Folder polls

docs/USER_GUIDE.md

@@ -78,7 +78,7 @@ Toolbar buttons, left to right:
 
 *   **Add files** / **Add folder**: load individual images or every image in a folder. Pick a folder that only holds *other* folders and NegPy reveals it in the Library section instead of reporting that it found nothing. Dropping a folder on the window does the same.
 *   **Clear all**: unload everything (or, when several frames are selected, unload just those).
-*   **Hot Folder**: watches the current folder and auto-loads new files as they appear, handy when a scanner drops files into a directory.
+*   **Hot Folder**: watches the current folder and auto-loads new files as they appear, handy when a scanner or tethering app drops files into a directory. While it is on, the "Working…" import popup stays hidden so each new frame does not raise a window; the status line over the canvas still reports the import.
 *   **RGB Scan**: treats the folder as red/green/blue exposure triplets and assembles each frame from three shots (for narrowband trichrome scanning). Right-click a frame → **Edit RGB Triplet…** to assign the three files by hand.
 *   **Half Frame**: splits each scan into two frames (for half-frame cameras), edited and metered separately. When enabled, a rectangle editor opens on the current scan: drag the green box to crop (everything outside is discarded), drag the orange line to set the split, and use the **Cut thickness** slider to discard a band centered on the split (the physical black separator between the two exposures). The setting is saved and applied to every half-frame split from then on, regardless of how the scans were acquired (SANE scanner, camera copy-stand, or folder import). The **Adjust Half Frame** toolbutton (next to Half Frame) re-opens the editor on the current scan to fine-tune. Auto-detection of the gutter still seeds the initial split position.
 *   **Apply (clone)**: copy the current frame's settings to selected frames or the whole roll. You choose which aspects in a dialog (crop and rotation are always per-image).

negpy/desktop/view/main_window.py

@@ -461,7 +461,7 @@ def _connect_signals(self) -> None:
         self.controller.status_progress_requested.connect(self.canvas.hud.set_progress)
 
         self.progress_dialog = ProgressDialog(self)
-        self.controller.batch_started.connect(self.progress_dialog.start)
+        self.controller.batch_started.connect(self._on_batch_started)
         self.controller.batch_progress.connect(self.progress_dialog.set_progress)
         self.controller.batch_finished.connect(self.progress_dialog.finish)
         self.progress_dialog.abort_requested.connect(self.controller.abort_active_batch)
@@ -474,6 +474,14 @@ def _connect_signals(self) -> None:
     def _refresh_dashboard(self) -> None:
         self.toolbar.refresh_gpu_status()
 
+    def _on_batch_started(self, title: str, abortable: bool) -> None:
+        """Hot Folder polls every 2 s, so its per-frame import batches (the only
+        non-abortable ones) would pop the dialog on every capture. The HUD status
+        line still reports those; abortable batches always show the popup."""
+        if not abortable and self.session_panel.file_browser.hot_folder_btn.isChecked():
+            return
+        self.progress_dialog.start(title, abortable)
+
     def _save_printing_notes(self) -> None:
         """Write the marked-up work print. The annotated pixels are the canvas's own
         render, so the composing happens here rather than in an export worker."""