new_gui: remove focus-measure (unused in current beamline GUI)

Stop enabling/displaying the per-frame focus metric; also lightens the camera
thread's per-frame work.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/aare/gui/new_gui/README.md

@@ -61,10 +61,11 @@ Backend contract is documented in the `new-gui-backend-paths` memory.
 - **Baton** chip ← `baton_status_changed`.
 - **Sample list** ← `spreadsheet` → Sample Changer + Library.
 - **Camera** ← `PredictionSubscriber` (live SAMCAM image, fps, target point).
-  ML detection overlays (boxes + convex-hull polygons, per-class colours), a
-  state-coloured beam-centre marker (`geom.beam_location_pxl`), and a focus
-  readout (`focus_measure`). Camera controls (⚙ gain/exposure → `samcam_settings`,
-  AF → `autofocus`, ◉ → `send_screenshot_db`) live in the tab strip.
+  ML detection overlays (boxes + convex-hull polygons, per-class colours) and a
+  state-coloured beam-centre marker (`geom.beam_location_pxl`). Inline camera
+  Exp/Gain (`samcam_settings`), AF (`autofocus`), and screenshot
+  (`send_screenshot_db`) live in the tab strip. (Focus-measure is disabled —
+  unused in the current beamline GUI.)
 - **Gonio / Beamline tabs** ← axis IP video via `VideoThread` (`frame_ready`).
 - **Staff Tools** (⚙ Tools in the top bar, staff only) — a tabbed dialog
   (`widgets/staff_tools.py`): **Beam/detector** (beam centre/size/mark, ABR

src/aare/gui/new_gui/ROADMAP.md

@@ -21,7 +21,7 @@ Start→`automated_scan`).
 - ML detection boxes/polygons (Crystal/Loop/Pin/Ice/Needle colours) ← `prediction_subscriber.prediction`
 - Beam-centre crosshair marker ← `status.geom.beam_location_pxl`
 - Camera exposure/gain controls + screenshot-to-DB(+metadata) ← `samcam_settings`, `send_screenshot_db`
-- Focus-measure readout ← `prediction_subscriber.focus_measure`
+- ~~Focus-measure readout~~ — removed (unused in the current beamline GUI)
 - Smargon bookmarks (Ctrl+click position markers) ← `models/bookmark.py`
 - Helical start/end markers (only if helical is in scope)
 

src/aare/gui/new_gui/main_window.py

@@ -305,10 +305,6 @@ class MainWindow(QWidget):
                 self.camera_thread.target_point.connect(cam.update_target_point)
             if hasattr(self.camera_thread, "prediction"):
                 self.camera_thread.prediction.connect(cam.update_predictions)
-            if hasattr(self.camera_thread, "focus_measure"):
-                self.camera_thread.focus_measure.connect(cam.update_focus)
-            if hasattr(self.camera_thread, "enable_focus_measurement"):
-                self.camera_thread.enable_focus_measurement(True)
             if hasattr(self.camera_thread, "update_daq_status"):
                 self.daq.update.connect(self.camera_thread.update_daq_status)
             # staff-view camera mirrors the same stream

src/aare/gui/new_gui/widgets/camera.py

@@ -58,7 +58,6 @@ class CameraViewport(QWidget):
         self._beam_px: QPoint | None = None        # beam centre, image-pixel coords
         self._beam_shutter = False
         self._beam_busy = False
-        self._focus: float | None = None
         self._detections: list = []                # raw boxes from prediction
         self._det_shape = None                     # [h, w] of the inference image
         self._show_detections = True
@@ -255,10 +254,6 @@ class CameraViewport(QWidget):
         self._beam_busy = bool(busy)
         self.update()
 
-    def update_focus(self, value: float) -> None:
-        self._focus = value
-        self.update()
-
     def update_predictions(self, payload: dict) -> None:
         if not isinstance(payload, dict):
             return
@@ -473,8 +468,6 @@ class CameraViewport(QWidget):
         painter.setFont(f)
         fps = "-" if self._fps != self._fps else f"{self._fps:.0f}"  # NaN-safe
         text = f"SAMCAM · {fps} fps · {self._zoom:.1f}×"
-        if self._focus is not None and self._focus == self._focus:  # NaN-safe
-            text += f" · focus {self._focus:.0f}"
         painter.drawText(QRect(0, 8, r.width() - 14, 16),
                          Qt.AlignRight | Qt.AlignTop, text)