feat(explore): enable heat map tooltips on click

[nikkikapadia]

this just enables the tooltip on heat map charts and shows the tooltip on click instead of on hover. I have to make the formatter for the tooltip so it's showing the default for now. Here's a demo of it working:

Screen.Recording.2026-05-12.at.3.55.21.PM.mov

[github-actions]

📊 Type Coverage Diff

✅ No new type safety issues introduced. Coverage: 93.50%

[sentry]

Bug: The heatmap tooltip formatter is not customized for 3D data, causing it to display the Y-axis label instead of the Z-axis count as the series value.
_{Severity: MEDIUM}

Suggested Fix

Provide a custom formatter function in the tooltip configuration for the heatmap chart. This formatter should correctly access the Z-axis value from the 3D series data at index 2 (e.g., params.value[2]) to display the correct count in the tooltip.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location:
static/app/views/dashboards/widgets/heatMapWidget/heatMapWidgetVisualization.tsx#L68-L73

Potential issue: The `tooltip` configuration for the heatmap chart in
`heatMapWidgetVisualization.tsx` lacks a custom `formatter`. Consequently, the default
formatter from `tooltip.tsx` is used, which is designed for 2D data and extracts the
value from index 1 of the series data (`getSeriesValue(serie, 1)`). For heatmap series,
which are 3D (`[xAxis, yAxis, zAxis]`), index 1 holds the Y-axis bucket label (e.g.,
'p95'), while the actual count is at index 2. This results in the tooltip incorrectly
displaying the Y-axis label as the metric value, misleading users about the data.

_{Did we get this right? 👍 / 👎 to inform future reviews.}

[nikkikapadia]

ya ya later problem