feat(blackjack): add action indicators and loading states

frontend/src/app/feature/game/blackjack/blackjack.component.html

@@ -5,10 +5,22 @@
     <div class="lg:col-span-3 space-y-6 flex flex-col gap-4">
       <app-dealer-hand [cards]="dealerCards()"></app-dealer-hand>
       <app-player-hand [cards]="playerCards()"></app-player-hand>
+      
+      <!-- Action message indicator -->
+      @if (isActionInProgress()) {
+        <div class="flex justify-center">
+          <div class="card p-4 flex items-center gap-3 animate-pulse bg-deep-blue-light border border-deep-blue-light/50">
+            <div class="w-5 h-5 rounded-full border-2 border-white border-t-transparent animate-spin"></div>
+            <span>{{ currentAction() }}</span>
+          </div>
+        </div>
+      }
+      
       @if (gameInProgress()) {
         <app-game-controls
           [playerCards]="playerCards()"
           [gameState]="gameState()"
+          [isActionInProgress]="isActionInProgress()"
           (hit)="onHit()"
           (stand)="onStand()"
           (doubleDown)="onDoubleDown()"
@@ -22,6 +34,7 @@
         [balance]="balance()"
         [currentBet]="currentBet()"
         [gameInProgress]="gameInProgress()"
+        [isActionInProgress]="isActionInProgress()"
         (newGame)="onNewGame($event)"
       ></app-game-info>
     </div>