feat(blackjack): add animated number component and usage

frontend/src/app/feature/game/blackjack/components/animated-number/animated-number.component.ts

@@ -0,0 +1,80 @@
+import { ChangeDetectionStrategy, Component, Input, OnChanges, SimpleChanges, ElementRef, ViewChild, AfterViewInit } from '@angular/core';
+import { CommonModule, CurrencyPipe } from '@angular/common';
+import { CountUp } from 'countup.js';
+
+@Component({
+  selector: 'app-animated-number',
+  standalone: true,
+  imports: [CommonModule, CurrencyPipe],
+  template: `
+    <span #numberElement>{{ formattedValue }}</span>
+  `,
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class AnimatedNumberComponent implements OnChanges, AfterViewInit {
+  @Input() value = 0;
+  @Input() duration = 1;
+  @Input() ease = 'power1.out';
+
+  @ViewChild('numberElement') numberElement!: ElementRef;
+
+  private countUp: CountUp | null = null;
+  private previousValue = 0;
+  formattedValue = '0,00 €';
+
+  ngAfterViewInit(): void {
+    this.initializeCountUp();
+    if (this.countUp && this.value !== 0) {
+      this.countUp.start(() => {
+        this.previousValue = this.value;
+      });
+    }
+  }
+
+  ngOnChanges(changes: SimpleChanges): void {
+    if (changes['value']) {
+      if (this.countUp) {
+        const startVal = this.previousValue;
+        const endVal = this.value;
+        
+        // Update the CountUp instance with new start and end values
+        this.countUp.update(endVal);
+        this.previousValue = endVal;
+      } else {
+        // Format the initial value if CountUp is not yet initialized
+        this.formattedValue = new Intl.NumberFormat('de-DE', {
+          style: 'currency',
+          currency: 'EUR',
+          minimumFractionDigits: 2,
+          maximumFractionDigits: 2,
+        }).format(this.value);
+      }
+    }
+  }
+
+  private initializeCountUp(): void {
+    if (this.numberElement) {
+      this.countUp = new CountUp(this.numberElement.nativeElement, this.value, {
+        startVal: this.previousValue,
+        duration: this.duration,
+        easingFn: (t, b, c, d) => {
+          // Custom easing function based on the input ease type
+          if (this.ease === 'power1.out') {
+            return c * (1 - Math.pow(1 - t / d, 1)) + b;
+          }
+          return c * (t / d) + b; // linear fallback
+        },
+        formattingFn: (value) => {
+          const formatted = new Intl.NumberFormat('de-DE', {
+            style: 'currency',
+            currency: 'EUR',
+            minimumFractionDigits: 2,
+            maximumFractionDigits: 2,
+          }).format(value);
+          this.formattedValue = formatted;
+          return formatted;
+        },
+      });
+    }
+  }
+}