fix(theme): overhaul light mode, remove silly themes

Light mode fixes:
- Darker surfaces (not pure white)
- Proper text colors (dark slate, not white)
- More opaque status colors for visibility
- Grey backdrop instead of harsh white

Removed themes (keeping only 3 good ones):
- Midnight (looked silly)
- Forest (looked silly)
- Dusk (looked silly)

Kept themes:
- Aurora (northern lights)
- Contrast (high contrast neon)
- Light (soft grey, now fixed)

src/components/shared/theme-toggle.tsx

@@ -5,12 +5,9 @@ import { Palette, Check } from 'lucide-react';
 import * as DropdownMenu from '@radix-ui/react-dropdown-menu';
 
 const themes = [
-  { id: 'aurora', name: 'Aurora', desc: 'Northern lights (teal & violet)' },
-  { id: 'midnight', name: 'Midnight', desc: 'Deep blue-purple' },
-  { id: 'forest', name: 'Forest', desc: 'Mossy green & amber' },
-  { id: 'dusk', name: 'Dusk', desc: 'Sunset orange & coral' },
-  { id: 'contrast', name: 'Contrast', desc: 'Pure black/white' },
-  { id: 'light', name: 'Light', desc: 'Clean & professional' },
+  { id: 'aurora', name: 'Aurora', desc: 'Northern lights' },
+  { id: 'contrast', name: 'Contrast', desc: 'High contrast neon' },
+  { id: 'light', name: 'Light', desc: 'Soft grey' },
 ] as const;
 
 export function ThemeToggle() {