Add a decimals option, fix dropdown overflow and the texture filter

- NumberField takes a decimals option (default 3); frame rects and the
  slice dialog use 0, matching their integer model.
- Button truncates its label to the drawn width; Dropdown reserves the
  chevron slot. NodeView reuses the shared truncate().
- Setting scaleMode leaves the style's shared resource id in place, so
  the old GPU sampler stayed in use until a reload. Call style.update().
- Graph gets a header bar like the Texture tab: GraphEditor is now the
  frame, the former editor is GraphCanvas. A selection the tab does not
  concern no longer unloads the behavior.
- New e2e step 14 guards text overflow across all widgets.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/editor/PlaySession.ts

@@ -132,7 +132,7 @@ export class PlaySession {
     // A destroyed entity removes its object – that is a structural change the lists must see.
     if (world.syncToModel()) this.state.preview();
     this.state.runtimeTick();
-    if (this.host.graphEditor.visible) this.host.graphEditor.redraw();
+    if (this.host.graphEditor.visible) this.host.graphEditor.canvas.redraw();
   }
 
   /** Read-only view of the running world for the check scripts. */