feat: camera session badge and collapsible legend

The camera overlay gains a clickable session badge (opens the session
menu at the click position) and a baton gate: watching stays free,
operating clicks are blocked when the baton is elsewhere. The legend
collapses to a ? badge until clicked - the full box covered too much
image.

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

src/aare/gui/widgets/camera_image.py

@@ -75,6 +75,7 @@ class SampleCameraImageState(Enum):
 
 class SampleCameraImageLabel(QGraphicsView):
     smargon = Signal(SmargonCoordinate)
+    session_badge_clicked = Signal()
 
     evaluate_grid = Signal()
     clear_grid = Signal()
@@ -107,6 +108,9 @@ class SampleCameraImageLabel(QGraphicsView):
         self._sam_cam = SampleCameraSettings(exposure=0.1, gain=100.0)
         self._is_daq_busy = False
         self._camera_available = True
+        # Baton gate: watching allowed, operating not (main_window drives it).
+        self._operations_allowed = True
+        self._session_badge_rect: QRect | None = None  # viewport coords
         self._last_grid_update_ts = 0.0
         self._grid_update_min_interval_s = 1.0 / 25.0
         self._tell_state = None
@@ -127,6 +131,10 @@ class SampleCameraImageLabel(QGraphicsView):
         self._show_target_coordinates = True
         self._show_overlay_legend = True
         self._compact_overlay_legend = False
+        # Legend stays collapsed to a "?" badge until clicked — the full box
+        # covers too much of the camera image to be always-on.
+        self._legend_expanded = False
+        self._legend_hit_rect: QRectF | None = None  # viewport coords, set on paint
         self._target_point = None
         self._target_shape = None
         self._target_color_name = "Cyan"
@@ -199,7 +207,14 @@ class SampleCameraImageLabel(QGraphicsView):
         )
 
     def _camera_interaction_enabled(self) -> bool:
-        return self._camera_available
+        # Watching is free; clicking (targets, raster, smargon moves) needs
+        # the camera AND the session baton.
+        return self._camera_available and self._operations_allowed
+
+    @Slot(bool)
+    def set_operations_enabled(self, enabled: bool):
+        self._operations_allowed = enabled
+        self.update()
 
     @Slot(bool)
     def set_camera_available(self, available: bool):
@@ -303,6 +318,7 @@ class SampleCameraImageLabel(QGraphicsView):
         painter.restore()
 
     def _draw_session_overlay(self, painter: QPainter):
+        self._session_badge_rect = None
         if self._busy_overlay_style is not None:
             return
 
@@ -343,6 +359,8 @@ class SampleCameraImageLabel(QGraphicsView):
         position_y = int((vh - bg_h) / 2)
 
         bg_rect = QRect(position_x, position_y, bg_w, bg_h)
+        # Clicking the badge opens the session (grab/request) menu.
+        self._session_badge_rect = bg_rect
 
         painter.setPen(QPen(qcolor(WHITE, 220)))
         painter.setBrush(bg_color)
@@ -406,6 +424,31 @@ class SampleCameraImageLabel(QGraphicsView):
         self._scaling()
 
     def mousePressEvent(self, event):
+        # Legend badge first: pure UI affordance, must work even when camera
+        # interaction is disabled (session overlay etc.).
+        if (
+            event.button() == Qt.MouseButton.LeftButton
+            and self._legend_hit_rect is not None
+            and self._legend_hit_rect.contains(
+                QPointF(self.viewport().mapFrom(self, event.pos()))
+            )
+        ):
+            self._legend_expanded = not self._legend_expanded
+            self.update()
+            event.accept()
+            return
+
+        # Session badge: the way IN when everything else is gated — must fire
+        # before the interaction-enabled check below.
+        if (
+            event.button() == Qt.MouseButton.LeftButton
+            and self._session_badge_rect is not None
+            and self._session_badge_rect.contains(self.viewport().mapFrom(self, event.pos()))
+        ):
+            self.session_badge_clicked.emit()
+            event.accept()
+            return
+
         if not self._camera_interaction_enabled():
             if event.button() in (Qt.MouseButton.LeftButton, Qt.MouseButton.RightButton):
                 self._show_camera_unavailable_tooltip(event)
@@ -930,10 +973,38 @@ class SampleCameraImageLabel(QGraphicsView):
 
         return lines
 
+    def _draw_legend_badge(self, painter: QPainter):
+        # ponytail: painted circle, not a real QWidget button — the legend it
+        # toggles is painter-drawn too, and a widget would need layout juggling.
+        diameter = 22
+        rect = QRectF(18, self.viewport().height() - diameter - 18, diameter, diameter)
+
+        painter.save()
+        painter.resetTransform()
+        painter.setRenderHint(QPainter.RenderHint.Antialiasing, True)
+        painter.setPen(QPen(qcolor(WHITE, 60), 1))
+        painter.setBrush(qcolor(LEGEND_BG, 170))
+        painter.drawEllipse(rect)
+
+        font = QFont()
+        font.setPointSize(10)
+        font.setBold(True)
+        painter.setFont(font)
+        painter.setPen(QPen(qcolor(LEGEND_TEXT), 1))
+        painter.drawText(rect, Qt.AlignmentFlag.AlignCenter, "?")
+        painter.restore()
+
+        self._legend_hit_rect = rect
+
     def _draw_overlay_legend(self, painter: QPainter):
+        self._legend_hit_rect = None
         if not self._legend_should_show():
             return
 
+        if not self._legend_expanded:
+            self._draw_legend_badge(painter)
+            return
+
         painter.save()
         painter.resetTransform()
         painter.setRenderHint(QPainter.RenderHint.Antialiasing, True)
@@ -959,6 +1030,7 @@ class SampleCameraImageLabel(QGraphicsView):
         height = len(lines) * line_height + 16
 
         bg_rect = QRectF(left, max(18, top), width, height)
+        self._legend_hit_rect = bg_rect  # click anywhere on the box to collapse
         painter.setPen(QPen(qcolor(WHITE, 60), 1))
         painter.setBrush(qcolor(LEGEND_BG, 170))
         painter.drawRoundedRect(bg_rect, 8, 8)

src/aare/gui/widgets/status_bar.py

@@ -334,7 +334,7 @@ class StatusBar(QStatusBar):
 
         self.session_label.setText(text)
 
-    def show_session_menu(self):
+    def show_session_menu(self, global_pos: QPoint | None = None):
         menu = QMenu(self)
         is_busy = self._status and self._status.busy
         session_state = self._status.session.session if self._status else SessionsStateEnum.Vacant
@@ -413,10 +413,16 @@ class StatusBar(QStatusBar):
             action_force = menu.addAction("⚠️ Force Take Over")
             action_force.triggered.connect(self._on_force_session_clicked)
 
-        label_geometry = self.session_label.geometry()
-        menu_width = max(label_geometry.width(), menu.sizeHint().width())
-        menu.move(self.mapToGlobal(label_geometry.topLeft()) - QPoint(0, menu.sizeHint().height()))
-        menu.setFixedWidth(menu_width)
+        if global_pos is not None:
+            # Invoked from the camera's session badge — open at the click.
+            menu.move(global_pos)
+        else:
+            label_geometry = self.session_label.geometry()
+            menu_width = max(label_geometry.width(), menu.sizeHint().width())
+            menu.move(
+                self.mapToGlobal(label_geometry.topLeft()) - QPoint(0, menu.sizeHint().height())
+            )
+            menu.setFixedWidth(menu_width)
         menu.exec()
 
     def show_pgroup_menu(self):