feat(types): add data_visualization Block Kit block

[zimeg]

Summary

Adds the net-new data_visualization Block Kit block to @slack/types.

• New DataVisualizationBlock interface (type: 'data_visualization', required title <=50 chars, required chart).
• Nested chart types: DataVisualizationPieChart (segments[], 1-6) and DataVisualizationSeriesChart (bar/area/line with series[] 1-6 + axis_config), unioned as DataVisualizationChart.
• Supporting object types: DataVisualizationPieSegment, DataVisualizationSeries, DataVisualizationDataPoint, DataVisualizationAxisConfig.
• Added DataVisualizationBlock to the KnownBlock union (alphabetical placement, after ContextActionsBlock).
• Follows existing conventions in blocks.ts (interface extending Block, JSDoc with @description + @see doc link, literal type discriminant).

Docs

https://docs.slack.dev/reference/block-kit/blocks/data-visualization-block

Validation

Run in packages/types:

• npm run build — pass (tsc clean)
• npm run test:types (tsd) — pass; added happy/sad-path assertions in test/blocks.test-d.ts mirroring the existing CardBlock/AlertBlock/CarouselBlock tests
• biome lint/format (pre-commit hook) — pass

Added a changeset (@slack/types minor).

🤖 Generated with Claude Code

[changeset-bot]

🦋 Changeset detected

Latest commit: 786019e

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@slack/types	Minor

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.12%. Comparing base (abf184e) to head (786019e).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2637   +/-   ##
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  Coverage   89.12%   89.12%           
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  Files          65       65           
  Lines       10441    10441           
  Branches      482      481    -1     
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  Hits         9306     9306           
  Misses       1103     1103           
  Partials       32       32           

Flag	Coverage Δ
cli-hooks	89.12% <ø> (ø)
cli-test	89.12% <ø> (ø)
logger	89.12% <ø> (ø)
oauth	89.12% <ø> (ø)
socket-mode	89.12% <ø> (ø)
web-api	89.12% <ø> (ø)
webhook	89.12% <ø> (ø)

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