feat: implement white balance feature with eyedropper tool

[tlambert03]

Screen.Recording.2026-03-29.at.4.14.03.PM.mov

[codecov]

Codecov Report

❌ Patch coverage is 50.39370% with 63 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.13%. Comparing base (8d46c1b) to head (ca3876e).
⚠️ Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
src/ndv/controllers/_array_viewer.py	23.63%	42 Missing ⚠️
src/ndv/views/_wx/_array_view.py	60.00%	8 Missing ⚠️
src/ndv/views/_qt/_array_view.py	73.91%	6 Missing ⚠️
src/ndv/views/_jupyter/_array_view.py	80.00%	2 Missing ⚠️
src/ndv/views/_pygfx/_array_canvas.py	33.33%	2 Missing ⚠️
src/ndv/views/_vispy/_array_canvas.py	33.33%	2 Missing ⚠️
src/ndv/models/_resolve.py	88.88%	1 Missing ⚠️

❌ Your patch check has failed because the patch coverage (50.39%) is below the target coverage (85.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #269      +/-   ##
==========================================
- Coverage   85.85%   85.13%   -0.72%     
==========================================
  Files          50       50              
  Lines        5853     5975     +122     
==========================================
+ Hits         5025     5087      +62     
- Misses        828      888      +60     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.