Territory abilities and clearer ownership

What changed

• Citadels retain the owner's vivid ship color instead of shifting with HP.
• Neutral citadels use a bright white treatment.
• Ship and outpost materials are lighter and clearer against the dark galaxy.
• Seven ability types remain active only while their citadel is controlled.
• Territory regions, continents, capitals, and supply lines communicate strategic connections.

These changes make damage, ownership, and ability control separate visual signals.