fix(calendar): clean up d3-tip tooltips

[sadpandajoe]

fix(calendar): clean up d3-tip tooltips

SUMMARY

• Adds Calendar Heatmap-specific d3-tip classes, including an owner-scoped class per mounted chart, so tooltip cleanup does not affect other chart instances.
• Destroys previous Calendar Heatmap instances for the same container before redraw and sweeps disconnected chart tooltip nodes after unmount.
• Destroys the vendor Calendar Heatmap cell and legend d3-tip instances when the calendar instance is destroyed.

Fixes #41583

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

Not applicable; tooltip cleanup is covered by DOM-level regression tests.

TESTING INSTRUCTIONS

• cd superset-frontend && NODE_ENV=test NODE_OPTIONS='--max-old-space-size=8192' npx jest --runInBand --silent plugins/legacy-plugin-chart-calendar/test/tooltip.test.ts plugins/legacy-plugin-chart-calendar/test/utils.test.ts
• cd superset-frontend && npx oxlint --config oxlint.json plugins/legacy-plugin-chart-calendar/src/Calendar.ts plugins/legacy-plugin-chart-calendar/src/ReactCalendar.tsx plugins/legacy-plugin-chart-calendar/src/tooltip.ts plugins/legacy-plugin-chart-calendar/src/vendor/cal-heatmap.ts plugins/legacy-plugin-chart-calendar/test/tooltip.test.ts

ADDITIONAL INFORMATION

• Has associated issue: Tooltips in the calendar heat map charts can remain in DOM even when navigating away from a dashboard #41583
• Required feature flags: none
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)

[codecov]

Codecov Report

❌ Patch coverage is 65.00000% with 14 lines in your changes missing coverage. Please review.
✅ Project coverage is 65.40%. Comparing base (8ce6d42) to head (9ffca6d).

Files with missing lines	Patch %	Lines
...ugins/legacy-plugin-chart-calendar/src/Calendar.ts	0.00%	12 Missing ⚠️
...lugins/legacy-plugin-chart-calendar/src/tooltip.ts	91.30%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #41589      +/-   ##
==========================================
+ Coverage   64.44%   65.40%   +0.96%     
==========================================
  Files        2751     2695      -56     
  Lines      154313   149770    -4543     
  Branches    35362    34727     -635     
==========================================
- Hits        99440    97955    -1485     
+ Misses      52962    50049    -2913     
+ Partials     1911     1766     -145     

Flag	Coverage Δ
javascript	70.75% <65.00%> (+0.25%)	⬆️

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[rusackas]

This one looks pretty well buttoned up. Anything keeping it in draft? Happy to take a proper review pass whenever you flip it to mergeable.