feat(glyph): consolidate plugin-chart-ag-grid-table to defineChart()

Replace the legacy ChartPlugin class wrapper with defineChart(). Same
light-touch consolidation used for plugin-chart-table: keep
buildQuery.ts, transformProps.ts, controlPanel.tsx, and AgGridTableChart
as separate modules and just import them into the thin defineChart entry.

210 plugin tests still pass.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>