fix: selection rect should reflect viewport change (#12355)

Fixes [BS-3349](https://linear.app/affine-design/issue/BS-3349/)

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

- **New Features**
  - Improved edge scrolling during selection dragging for smoother and more responsive viewport navigation.
  - Dragging area and mouse position tracking now update reactively with viewport changes, ensuring more accurate selection and movement.

- **Refactor**
  - Unified and clarified coordinate handling for dragging and mouse position, with clearer naming and separation between model and browser coordinates.
  - Simplified selection logic and removed unnecessary accumulated state for cleaner and more maintainable behavior.
  - Enhanced flexibility in coordinate conversion by allowing viewport transformations relative to arbitrary zoom and center.
  - Streamlined clipboard paste handling by simplifying mouse position extraction and adjusting attachment options.

- **Bug Fixes**
  - Enhanced overlay and dragging area accuracy by updating position calculations and coordinate transformations.
  - Fixed paste operations to correctly handle mouse position without unnecessary coordinate conversions.
  - Corrected drag initiation positions in toolbar and shape dragging to align with viewport-relative coordinates.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/widgets/edgeless-dragging-area/src/edgeless-dragging-area-rect.ts

@@ -36,7 +36,7 @@ export class EdgelessDraggingAreaRectWidget extends WidgetComponent<RootBlockMod
   }
 
   override render() {
-    const rect = this.gfx.tool.draggingViewArea$.value;
+    const rect = this.gfx.tool.draggingViewportArea$.value;
     const tool = this.gfx.tool.currentTool$.value;
 
     if (