feat: enable panning by dragging on empty space with left mouse button

src/interaction/modes/Cursor.ts

@@ -142,6 +142,15 @@ export const Cursor: ModeActions = {
         items: [item],
         isInitialMovement: true
       });
+    } else {
+      // If no item is being dragged and the mouse has moved, switch to PAN mode
+      // Only do this if the drag started on empty space
+      if (uiState.mouse.mousedown) {
+        uiState.actions.setMode({
+          type: 'PAN',
+          showCursor: false
+        });
+      }
     }
   },
   mousedown,

src/interaction/modes/Pan.ts

@@ -27,7 +27,13 @@ export const Pan: ModeActions = {
 
     setWindowCursor('grabbing');
   },
-  mouseup: () => {
+  mouseup: ({ uiState }) => {
     setWindowCursor('grab');
+    // Always revert to CURSOR mode after panning
+    uiState.actions.setMode({
+      type: 'CURSOR',
+      showCursor: true,
+      mousedownItem: null
+    });
   }
 };