fix(values): fix focused cell persistence and restoration across reopen

[bosiakov]

• Suppress focused cell persistence while a chart's saved UI state is loading
• Sync the last focused row and column trackers during the load window so no stale save fires once loading completes
• Keep the pending focus key across frames and re-resolve it by key each frame until focus lands
• Clear the pending focus key when the focus highlight completes
• Reset the awaiting focus restore flag on chart open and when the saved state load finishes