[gioxx]

Closes #182

Stacked on #181.

What changes

Search in long checklist filters (ColumnFilterButton)

• Checklists with more than 10 values get a search box above the list (focused when the filter opens). It matches the option labels.
• Select all acts on the values the search shows: checking it adds them, unchecking it removes them, and its mixed state is computed on those values.
• "No values match." when the search finds nothing.
• The stored selection is normalized to the current options, so a value that no longer exists cannot keep Select all unchecked.

Keyboard focus in table popovers (TablePopover, used by the column filters and Columns)

• Tab on the last control, or Shift+Tab on the first, closes the popover and returns focus to its button, instead of leaving the page with the popover still open.
• The funnel button no longer has aria-pressed (it was announced as a toggle). Its accessible name adds "(filtered)" when the column has a filter; aria-expanded and aria-haspopup="dialog" stay.

i18n: common.table.searchValues, noValues, filtered (en, it).

Testing

• npm test (285 pass), npm run lint, check:i18n and vite build pass.
• Local install, Audit admin filter (15 values): the search box gets focus; searching narrows the list; Select all on the results filters only those admins (125 to 120 events, matching the API); the button name reads "Filter: Admin (filtered)"; Tab from the last control closes the popover and focuses the funnel.
• Not covered by automated tests: the React side (no DOM test environment).