feat(themes): add new premium themes and overhaul legacy ones

Add 7 themes: Obsidian, Ember, Dusk, Carbon, Mint,
   Sandstone, and Blossom — each with unique color identities spanning
   both dark and light variants.

   Redesign 6 legacy themes (Bump, Bling, Moon, Atticus, Tomyris, Menes)
   that had poor contrast, unreadable colored body text, clashing accent
   colors, and missing properties. All now have proper text contrast,
   cohesive palettes, and complete property coverage including
   errorTextColor, dangerColor, scrollbarColor, boxShadowColor, and
   activeTextColor

Author: bajrangCoder