Unify pathfinding visualize; update About CSS

Consolidate separate visualizeDijkstra/visualizeAStar into a single visualize(algorithm) method and update the template buttons to call visualize('dijkstra') or visualize('astar'). The new method dispatches to the appropriate pathfindingService method, centralizes timing/animation handling, and reduces duplicated logic. Also apply minor About page styling tweaks: add left margin to the Experience h2 and remove the .xp-list rules from the SCSS (small cleanup/reformat).

src/app/pages/about/about.component.html

@@ -66,7 +66,7 @@
   </mat-card>
 
   <mat-card class="experdience">
-    <h2>{{ 'ABOUT.SECTION.EXPERIENCE' | translate }}</h2>
+    <h2 style="margin-left: 0.5rem;">{{ 'ABOUT.SECTION.EXPERIENCE' | translate }}</h2>
     <div class="xp-list">
       @for (entry of xpKeys; track entry.key) {
         <div class="xp-item">