feat(deposit): implement modal animations with GSAP

frontend/src/app/shared/services/modal-animation.service.ts

@@ -0,0 +1,53 @@
+import { Injectable } from '@angular/core';
+import gsap from 'gsap';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class ModalAnimationService {
+  private readonly defaultDuration = 0.3;
+  private readonly defaultEase = 'power2.out';
+
+  openModal(modalElement: HTMLElement, overlayElement: HTMLElement) {
+    gsap.set(overlayElement, { opacity: 0, display: 'block' });
+    gsap.set(modalElement, { 
+      opacity: 0, 
+      scale: 0.95,
+      y: 20,
+      display: 'block'
+    });
+
+    gsap.to(overlayElement, {
+      opacity: 1,
+      duration: this.defaultDuration,
+      ease: this.defaultEase
+    });
+
+    gsap.to(modalElement, {
+      opacity: 1,
+      scale: 1,
+      y: 0,
+      duration: this.defaultDuration,
+      ease: this.defaultEase
+    });
+  }
+
+  closeModal(modalElement: HTMLElement, overlayElement: HTMLElement, onComplete?: () => void) {
+    gsap.to([overlayElement, modalElement], {
+      opacity: 0,
+      duration: this.defaultDuration,
+      ease: this.defaultEase,
+      onComplete: () => {
+        gsap.set([overlayElement, modalElement], { display: 'none' });
+        onComplete?.();
+      }
+    });
+
+    gsap.to(modalElement, {
+      scale: 0.95,
+      y: 20,
+      duration: this.defaultDuration,
+      ease: this.defaultEase
+    });
+  }
+}