c50eaf81f7
HighContrastBackground gains an optional hc_color field so sites can specify a domain-specific HC variant rather than always bumping to BORDER_SUBTLE_HC (gray). with_default() fills hc_color = BORDER_SUBTLE_HC preserving all existing behaviour; new with_hc(default, hc) lets callers specify both ends. update_high_contrast_backgrounds reads marker.hc_color instead of the hardcoded constant. STATE_SUCCESS_HC (#c8e862, L≈0.73) added to ui_theme — a brighter lime that maintains the success hue while standing out from bumped notch ticks (BORDER_SUBTLE_HC gray, L≈0.60) under HC mode. WIN MOVE marker now carries HighContrastBackground::with_hc(STATE_SUCCESS, STATE_SUCCESS_HC): lime stays lime under HC instead of turning gray. Unit test pins both the default and hc color fields on the spawned marker. 1276 tests pass / 0 failing. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>