perf(charts): import chart components from @gpustack/core-ui/charts

Switch all echarts-based chart imports to the dedicated core-ui charts
entry so echarts stays out of the synchronous entry bundle and loads
only on chart routes. Requires @gpustack/core-ui with the ./charts export.

src/pages/dashboard/components/usage-charts/top-token-usage-by-user.tsx

@@ -1,4 +1,4 @@
-import { HBarChart } from '@gpustack/core-ui';
+import { HBarChart } from '@gpustack/core-ui/charts';
 import { useIntl } from '@umijs/max';
 import { usageChartHeight, usageRankMaxItems } from '../../config';
 import type useTopTokenUsageByUser from '../../hooks/use-top-token-usage-by-user';