feat(canvas): enhance edge insertion animations and update reflow duration

- Added a new CSS animation for edge insertion to improve visual feedback during node creation.
- Updated the edge insertion reflow duration from 997ms to 1297ms for smoother transitions.
- Refactored related components to support the new animation and ensure consistent behavior across the canvas.
- Enhanced tests to validate the new edge insertion features and animations.

components/canvas/use-canvas-edge-insertions.ts

@@ -27,7 +27,7 @@ export type EdgeInsertMenuState = {
 };
 
 const EDGE_INSERT_GAP_PX = 10;
-const DEFAULT_REFLOW_SETTLE_MS = 997;
+const DEFAULT_REFLOW_SETTLE_MS = 1297;
 
 function waitForReflowSettle(ms: number): Promise<void> {
   return new Promise((resolve) => {