feat: show locked beamline banners to non-staff

Beamline setup, ABR meas. pos. and Beam configuration banners stay
visible for non-staff instead of vanishing, but are locked stand-ins:
clicking one pops the staff-only notice (same pattern as the
Auxiliary-puck tab) telling the user to log in as staff or contact
their local contact.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/aare/gui/main_window.py

@@ -362,6 +362,10 @@ class MainWindow(QMainWindow):
         beamline_layout = QVBoxLayout(beamline_page)
         beamline_layout.setContentsMargins(0, 0, 0, 0)
         self.samcam = SamcamPanel(beamline_page)
+        # Non-staff keep the staff-only banners visible (locked stand-ins, a
+        # click explains the gate) so the Beamline tab reads the same for
+        # every role instead of looking amputated.
+        self._locked_beamline_banners: list[TitleLabel] = []
         if self._decoded_token.staff:
             self.monochromator_panel = MonochromatorPanel(beamline_page)
             self.abr_tweak = AbrTweakWidget(beamline_page)
@@ -372,6 +376,20 @@ class MainWindow(QMainWindow):
             beamline_layout.addWidget(self.monochromator_panel)
             beamline_layout.addWidget(self.abr_tweak)
             beamline_layout.addWidget(self.beam_config)
+        else:
+            for title in ("Beamline setup", "ABR meas. pos.", "Beam configuration"):
+                # Holder with default layout margins so the banner aligns with
+                # the real panels' banners (same trick as BeamConfigPanel).
+                holder = QWidget(beamline_page)
+                holder_layout = QVBoxLayout(holder)
+                holder_layout.setSpacing(0)
+                banner = TitleLabel(title, holder)
+                banner.setCursor(Qt.CursorShape.PointingHandCursor)
+                banner.setToolTip("Only accessible for beamline scientists")
+                banner.installEventFilter(self)
+                holder_layout.addWidget(banner)
+                beamline_layout.addWidget(holder)
+                self._locked_beamline_banners.append(banner)
         # Samcam last: the beam panels are the ones tweaked most.
         beamline_layout.addWidget(self.samcam)
         beamline_layout.addStretch()
@@ -403,7 +421,13 @@ class MainWindow(QMainWindow):
         # Dewar-tabs look: first banner flush under the tab bar (no top
         # margin) and the tab row starting at the banners' left edge. The
         # Experiment side needs two levels: the frame AND its first panel.
-        beamline_first = self.monochromator_panel if self._decoded_token.staff else self.samcam
+        beamline_first = (
+            self.monochromator_panel
+            if self._decoded_token.staff
+            # Non-staff: the first locked banner's holder is the column's
+            # first widget now, not samcam.
+            else self._locked_beamline_banners[0].parentWidget()
+        )
         for first in (beamline_first, self.data_collection, self.data_collection.file_path_panel):
             first_layout = first.layout()
             assert first_layout is not None  # panels build their layouts in __init__
@@ -1391,6 +1415,15 @@ class MainWindow(QMainWindow):
             "The Auxiliary puck (reference tools) view is available to staff accounts only.",
         )
 
+    def _show_beamline_staff_only_popup(self) -> None:
+        QMessageBox.information(
+            self,
+            "Staff only",
+            "Beamline configuration is available to staff accounts only.\n"
+            "Log in with a staff account or contact your local contact "
+            "to configure the beamline.",
+        )
+
     @Slot()
     def _raise_reference_tools(self) -> None:
         if not self._decoded_token.staff:
@@ -3182,6 +3215,11 @@ class MainWindow(QMainWindow):
         ):
             self._show_reference_tools_staff_only_popup()
             return True
+        # Non-staff click on a locked Beamline banner: same treatment as the
+        # Auxiliary-puck tab — explain the gate instead of eating the click.
+        if event.type() == QEvent.Type.MouseButtonPress and obj in self._locked_beamline_banners:
+            self._show_beamline_staff_only_popup()
+            return True
         return super().eventFilter(obj, event)
 
     def _start_remote_close_countdown(