The flag has defaulted to True and been marked deprecated; the
color-collision avoidance in CategoricalColorScale is now permanently
enabled. Removes the flag from config.py (docs feature-flags.json
regenerated), the test config override, the frontend FeatureFlag enum,
and both gated branches in getColor.
Tests: flag-off cases are removed or rewritten for the always-on
behavior, the two getNextAvailableColor tests seed usage counts
directly (getColor itself now redistributes collisions during setup),
and the suite-level beforeEach resets the labels color map singleton so
dashboard-sourced tests can no longer leak state between tests, which
the flag previously masked.
Closes#41044
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
