frontend: phi_min/phi_max columns in the azimuthal ROI table

Surface the optional azimuthal phi-sector bounds (phi_min_deg/phi_max_deg)
as editable columns, so a sector can be set from the web UI, not only the
viewer. Also fix the Q_max row's d header, which read d_max but is d_min.

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

frontend/src/components/ROI.tsx

@@ -318,8 +318,12 @@ function ROI({s: serverS}: MyProps) {
                 } else
                     return row;
             },
-            renderHeader: () => (<div>d<sub>max</sub> [Å]</div>)
+            renderHeader: () => (<div>d<sub>min</sub> [Å]</div>)
         },
+        { field: 'phi_min_deg', type: 'number', editable: true,
+            renderHeader: () => (<div>φ<sub>min</sub> [°]</div>) },
+        { field: 'phi_max_deg', type: 'number', editable: true,
+            renderHeader: () => (<div>φ<sub>max</sub> [°]</div>) },
         { field: 'actions', type: 'actions', width: 50, cellClassName: 'actions',
             getActions: (id : GridRowModel) => {
                 return [