fix: prevent scroll to top when switching tabs (#283)

Preserve scroll position when changing tabs by capturing scrollY before
navigation and restoring it after. This prevents the jarring scroll-to-top
behavior on both desktop and mobile when clicking tabs in slot/epoch detail
pages.

The fix uses requestAnimationFrame to ensure the scroll position is restored
after the browser has processed the URL change.

Author: samcm

src/hooks/useTabState/useTabState.ts

@@ -168,6 +168,9 @@ export function useTabState(tabs: TabConfig[]): UseTabStateReturn {
     // Check if current hash is an anchor within the NEW tab
     const hashBelongsToNewTab = newTab.anchors?.includes(currentHash);
 
+    // Store current scroll position before navigation
+    const scrollY = window.scrollY;
+
     if (hashBelongsToNewTab) {
       // Keep the anchor and scroll to it
       // eslint-disable-next-line @typescript-eslint/no-explicit-any, no-restricted-syntax
@@ -187,6 +190,12 @@ export function useTabState(tabs: TabConfig[]): UseTabStateReturn {
         replace: true,
         hash: undefined,
       });
+
+      // Restore scroll position after navigation to prevent scroll to top
+      // This prevents the jarring scroll behavior on both desktop and mobile
+      requestAnimationFrame(() => {
+        window.scrollTo(0, scrollY);
+      });
     }
   };