feat(datagrid): page-size menu, first/last buttons, and jump-to-page in the pagination bar

[datlechin]

Closes #1364.

Replaces the minimal pagination control (Prev / "N of M" / Next plus a gear popover for limit and offset) with a richer bar for table tabs.

What's new

• Rows-per-page menu: presets 5, 10, 20, 100, 500, 1,000, plus All rows (with a confirmation) and a Custom size.
• First / Previous / Next / Last page buttons.
• Click the page indicator to jump to a specific page.
• The bar now appears for filtered tables whose total row count is unknown, so you can page through them instead of seeing only the first page. Next stays available while a full page keeps loading; Last and jump-to-page need a known total.
• First Page and Last Page keyboard actions, unbound by default, assignable in Settings > Keyboard.

Design notes

• The pagination model and coordinator were already complete, so this is mostly a view rebuild plus a small coordinator addition (goToPage, unknown-total Next, Show All). The table-browse data-loading path is unchanged.
• Native macOS controls: a borderless pop-up Menu for page size, four borderless SF Symbol buttons for navigation, and a popover with a text field for jump-to-page. macOS has no page-number or page-dots control (per the HIG), so there is no web-style pager.
• Unknown-total tables use the loaded-row-count signal to decide whether a next page exists, instead of a pageSize + 1 probe, which keeps the data-loading path untouched. Trade-off: a table whose size is an exact multiple of the page size with an unknown total can show one empty page on Next (rare, self-correcting).
• Default page size stays 1,000.

Tests

• New PaginationState tests: isLastPageKnown, canGoToNextPage with known and unknown totals, goToNextPage(loadedRowCount:), goToPage guard with an unknown total.
• New PaginationCoordinatorTests: goToPage routing, and Next/Last behavior on an unknown total.

Notes

• New user-facing strings use String(localized:); the String Catalog picks them up on the next Xcode build, so Localizable.xcstrings should be committed after building.
• Not built locally yet; relying on CI / your Xcode build for the compile.