feat(materials): free rotate session overlays and show save progress

Match NPC drag-to-rotate on the material frame during playback, and change the add/edit Save button to Saving… while import runs.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/renderer/control/ControlApp.tsx

@@ -1593,12 +1593,12 @@ export function ControlApp() {
               return (
                 <MaterialOverlay
                   assetId={activeMaterial.assetId}
-                  rotationDeg={activeMaterial.rotationDeg ?? 0}
                   layout={materialsOverlay?.layout ?? DEFAULT_MATERIALS_OVERLAY_LAYOUT}
                   editable
                   zoomTool={materialsOverlay?.zoomTool ?? null}
                   showClose
                   closeLabel={t('materials.closeOverlay')}
+                  rotateLabel={t('materials.rotateOverlay')}
                   onClose={() => {
                     void materialsApi.dispatch({ kind: 'hide' });
                   }}