<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** For #43769
# Details
This PR adds "Hosts active" and "Hosts enrolled" charts to the
dashboard.
New components:
* **ChartCard.tsx**: encapsulates a visualization-agnostic chart, for
data provided by the new `/charts` endpoint created in
https://github.com/fleetdm/fleet/pull/43910
* **ChartFilterModal.tsx**: modal for setting filters on a chart.
Currently supports filtering by label, platform and individual host.
* **CheckerboardViz.tsx**: a checkerboard visualization for use in
ChartCard. Capable of charting 1, 7, 14 or 30 days at a time, although
only 30 day charts are used right now. Bespoke rendering using SVG,
since recharts scatterchart was harder to wrangle than it was worth.
* **LineChartViz.tsx**: a line-chart visualization using Recharts
* **HostsEnrolledCard.tsx**: a bar chart of enrolled hosts using
Recharts
# Checklist for submitter
If some of the following don't apply, delete the relevant line.
- [X] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/guides/committing-changes.md#changes-files)
for more information.
## Testing
- [X] Added/updated automated tests
- [X] QA'd all new/changed functionality manually
- With backend provided by https://github.com/fleetdm/fleet/pull/43910:
<img width="1426" height="428" alt="image"
src="https://github.com/user-attachments/assets/0f53b9d1-c87b-4225-a175-2d40af5afe41"
/>
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Dashboard now shows interactive "Hosts active" (line/heatmap) and
"Hosts enrolled" (bar) charts with metric selection, filter modal
(labels/platforms/hosts), legends, tooltips, and responsive layout.
* **Tests**
* Added comprehensive tests covering chart rendering, checkerboard
heatmap, and no-data states.
* **Chores**
* Added charting library dependency to support visualizations.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Scott Gress
207c3058c5