Add a sortable "Out/In Ratio" (completion_tokens / prompt_tokens)
column with a portal-based tooltip explaining the metric. Fix
hydration mismatch by switching to useSyncExternalStore for
localStorage reads in TimeRangeProvider. Update CLAUDE.md with
project documentation.
Lift time range state into a shared React context so the selected
range persists across page navigation and browser refreshes
(localStorage). Add a "Custom" option with a popover date picker
that lets users specify arbitrary start/end dates. All preset end
times now use endOf("day") (23:59:59) instead of the current moment.
