viewer: ROI list panel — select, add, rename, delete, per-ROI results

Add JFJochViewerROIList to the side panel: a list of the dataset's ROIs
with selection, add (box/circle/azimuthal), rename and delete, plus a
statistics readout (sum/mean/std/max/valid/masked/centre-of-mass) for the
selected ROI, taken from the analysis output for the current image. Edits
emit a full ROIDefinition, routed to the worker's SetROIDefinition.

Per-ROI statistics now live in this panel rather than the canvas labels;
the diffraction image's labels show only the ROI name, and the ad-hoc
ROIIntegrationCPU computation there is removed in favour of the analysis
pipeline. The result widget now reports std dev instead of variance.

The single-ROI scratch panel remains for now and will be retired once the
interactive canvas editing replaces it.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

viewer/JFJochViewerWindow.cpp

@@ -204,6 +204,9 @@ JFJochViewerWindow::JFJochViewerWindow(QWidget *parent, bool dbus, const QString
     connect(viewer, &JFJochDiffractionImage::roiCalculated,
             side_panel, &JFJochViewerSidePanel::SetROIResult);
 
+    connect(side_panel, &JFJochViewerSidePanel::roisChanged,
+            reading_worker, &JFJochImageReadingWorker::SetROIDefinition);
+
     connect(side_panel, &JFJochViewerSidePanel::ROIBoxConfigured,
             reading_worker, &JFJochImageReadingWorker::SetROIBox);