fix(datagrid): reflect active filters in row count and pagination

[datlechin]

What

Filtering a table now updates the row count and page count in the bottom-right to match the filtered result, instead of showing the whole-table totals.

How

• Adds fetchFilteredRowCount(table:filters:logicMode:) to the PluginDatabaseDriver protocol, with a default implementation returning nil so a driver that can't count a filtered set falls back to the previous behavior.
• Bridges the method through PluginDriverAdapter and DatabaseDriver; MongoDB implements it.
• TableQueryBuilder / QueryExecutionCoordinator use the filtered count to drive the footer count and pagination when a filter is active.

PluginKit ABI

This adds a protocol method, so it bumps PluginKit ABI 14 to 15 (currentPluginKitVersion plus every bundled plugin Info.plist). ABI 14 already shipped in v0.43.2, so this is a fresh, necessary bump, not a re-bump of an unreleased version.

After this merges to main, the registry plugins need rebuilding against ABI 15:

./scripts/release-all-plugins.sh 15

Tests

• TableQueryBuilderFilterTests covers the filtered-count query construction.