feat(grid): remember scroll position per view

[markov12]

Problem

The grid always opens scrolled to the top-left. On wide tables, or tables where new rows are appended at the bottom, you have to scroll back to where you were every time you switch views, switch tables or reload the page.

Change

Remember each grid view's scroll position (vertical and horizontal) in localStorage, keyed by user + view, and restore it when the view is opened again. If the view was scrolled to the bottom, it stays pinned to the bottom after new rows are appended, so freshly added rows remain visible.

• Grid gets an optional initialScrollState prop that seeds its scroll state on mount. GridViewBase already re-mounts the grid (via ViewSkeleton) on every view switch, so the restore is declarative and doesn't race the async layout with an imperative scrollTo.
• InfiniteScroller aligns the DOM scrollbars with that initial offset once they are actually scrollable, and syncs the touch Scroller with the real position (on mount and at the start of each gesture) — otherwise its internal offset is stale and the first swipe jumps back to the top.
• If the content no longer overflows (a resize, or a stale offset on a now-short view), the position snaps back to the top/left edge so the first rows/columns can't get stranded.
• useGridScrollPosition (app) computes the initial state from storage and persists on scroll: debounced (500 ms), try/catch-guarded, and it ignores the transient zeros emitted while the grid lays out, so they can't overwrite the saved position.

Browser-only, no server or schema changes. Grid behaves exactly as before when initialScrollState isn't passed.

Testing

Manually tested on desktop and in Chrome device emulation (touch):

• reload, switching tables / views and back — vertical and horizontal position restored
• scrolled to the bottom / right edge, then switch away and back — stays at the bottom / edge
• adding and deleting rows, resizing the window, collapsing / expanding the sidebar
• touch: first swipe after coming back starts from the restored position

🤖 Generated with Claude Code

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[markov12]

Hi! Just a quick note that the CLA check is now passing. Is there anything else I should do on my side to move this forward? Happy to rebase or adjust the implementation if needed. Thanks!