feat: redesign all share cards, remove unused achievement types, fix sport selector

Redesign trip, progress, and achievement share cards with premium
sports-media aesthetic. Remove unused milestone/context achievement card
types (only used in debug exporter). Fix gold text unreadable in light
mode. Fix sport selector to only show stroke on selected sport.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

SportsTime/Export/Sharing/ShareService.swift

@@ -101,7 +101,7 @@ enum ShareThemePreferences {
         switch cardType {
         case .tripSummary:
             return tripTheme
-        case .achievementSpotlight, .achievementCollection, .achievementMilestone, .achievementContext:
+        case .achievementSpotlight, .achievementCollection:
             return achievementTheme
         case .stadiumProgress:
             return progressTheme
@@ -112,7 +112,7 @@ enum ShareThemePreferences {
         switch cardType {
         case .tripSummary:
             tripTheme = theme
-        case .achievementSpotlight, .achievementCollection, .achievementMilestone, .achievementContext:
+        case .achievementSpotlight, .achievementCollection:
             achievementTheme = theme
         case .stadiumProgress:
             progressTheme = theme