feat(ExpanableWrapper): add onResize prop and trigger it in ResizeObserver

src/shared/ui/ExpandableWrapper/ExpandableWrapper.svelte

@@ -3,6 +3,7 @@
     Animated wrapper for content that can be expanded and collapsed.
 -->
 <script lang="ts">
+import { debounce } from '$shared/lib/utils';
 import { cn } from '$shared/shadcn/utils/shadcn-utils';
 import type { Snippet } from 'svelte';
 import { cubicOut } from 'svelte/easing';
@@ -38,6 +39,10 @@ interface Props extends HTMLAttributes<HTMLDivElement> {
      * Optional badge to render
      */
     badge?: Snippet<[{ expanded?: boolean; disabled?: boolean }]>;
+    /**
+     * Callback for when the element's size changes
+     */
+    onResize?: (rect: DOMRectReadOnly) => void;
     /**
      * Rotation animation direction
      * @default 'clockwise'
@@ -56,6 +61,7 @@ let {
     visibleContent,
     hiddenContent,
     badge,
+    onResize,
     rotation = 'clockwise',
     class: className = '',
     containerClassName = '',
@@ -64,7 +70,7 @@ let {
 
 let timeoutId = $state<ReturnType<typeof setTimeout> | null>(null);
 
-export const xSpring = new Spring(0, {
+const xSpring = new Spring(0, {
     stiffness: 0.14, // Lower is slower
     damping: 0.5, // Settle
 });
@@ -79,7 +85,7 @@ const scaleSpring = new Spring(1, {
     damping: 0.65,
 });
 
-export const rotateSpring = new Spring(0, {
+const rotateSpring = new Spring(0, {
     stiffness: 0.12,
     damping: 0.55,
 });
@@ -107,6 +113,9 @@ function handleKeyDown(e: KeyboardEvent) {
     }
 }
 
+// Create debounced recize callback
+const debouncedResize = debounce((entry: ResizeObserverEntry) => onResize?.(entry.contentRect), 50);
+
 // Elevation and scale on activation
 $effect(() => {
     if (expanded && !disabled) {
@@ -149,6 +158,21 @@ $effect(() => {
         expanded = false;
     }
 });
+
+// Use an effect to watch the element's actual physical size
+$effect(() => {
+    if (!element) return;
+
+    const observer = new ResizeObserver(entries => {
+        const entry = entries[0];
+        if (entry) {
+            debouncedResize(entry);
+        }
+    });
+
+    observer.observe(element);
+    return () => observer.disconnect();
+});
 </script>
 
 <div
@@ -158,7 +182,7 @@ $effect(() => {
     role="button"
     tabindex={0}
     class={cn(
-        'will-change-transform duration-300',
+        'will-change-[transform, width, height] duration-300',
         disabled ? 'pointer-events-none' : 'pointer-events-auto',
         className,
     )}