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">

src/app/pages/about/about.component.scss

@@ -47,7 +47,6 @@
 /* Skills block */
 .skills {
   padding: 5px;
-
   h2 { margin-top: .25rem; margin-left: .25rem; }
   .chip-groups {
     margin-left: .25rem;
@@ -64,11 +63,7 @@
 /* Experience block */
 .experience {
   padding: 5px;
-  h2 { margin-top: .25rem;margin-left: .25rem; }
-  .xp-list {
-    margin-left: .25rem;
-    display: grid; gap: .75rem;
-  }
+  h2 { margin-top: .25rem; margin-left: .25rem; }
   .xp-item {
     .xp-head {
       display:flex; align-items:baseline; gap:.5rem;