fix(router-core): stop forcing history.scrollRestoration to 'manual'

.changeset/scroll-restoration-browser-default.md

@@ -0,0 +1,5 @@
+---
+'@tanstack/router-core': patch
+---
+
+Stop forcing `history.scrollRestoration = 'manual'` when scroll restoration is enabled. The browser's native restoration runs before first paint, so forcing manual mode broke iOS Safari swipe-back previews and made Chrome paint at the top and snap down on hard refresh; the router's own restoration still runs afterwards and still restores individual scroll containers.

packages/router-core/src/scroll-restoration.ts

@@ -201,8 +201,6 @@ export function setupScrollRestoration(router: AnyRouter, force?: boolean) {
     scroll.restoration = true
     ignoreScroll = false
 
-    history.scrollRestoration = 'manual'
-
     document.addEventListener(
       'scroll',
       (event) => {

packages/router-core/tests/scroll-restoration.test.ts

@@ -70,7 +70,10 @@ describe('setupScrollRestoration', () => {
 
     expect(router._scroll.restoring).toBe(true)
     expect(router._scroll.restoration).toBe(true)
-    expect(window.history.scrollRestoration).toBe('manual')
+    // The browser's own restoration stays on: it handles the window before
+    // first paint (Safari swipe-back previews, hard refresh); the router only
+    // corrects afterwards and restores individual scroll containers.
+    expect(window.history.scrollRestoration).toBe('auto')
     expect(
       windowAddEventListener.mock.calls.some(([event]) => event === 'pagehide'),
     ).toBe(true)