feat(theme): complete theme overhaul with 6 polished themes

- Aurora: Real northern lights colors (teal/violet on deep blue-black)
- Midnight: Deep ocean blues with violet and cyan
- Forest: Rich forest greens with golden sunlight
- Dusk: Warm sunset oranges and corals
- Contrast: Pure black with neon accents
- Light: Clean professional light mode (NEW)

All themes have:
- Consistent status colors (green/amber/red)
- Distinct surface layers for visual hierarchy
- Theme-appropriate accent glows
- Improved contrast and accessibility

src/components/shared/theme-toggle.tsx

@@ -5,11 +5,12 @@ import { Palette, Check } from 'lucide-react';
 import * as DropdownMenu from '@radix-ui/react-dropdown-menu';
 
 const themes = [
-  { id: 'aurora', name: 'Aurora', desc: 'Warm charcoal + cyan' },
-  { id: 'midnight', name: 'Midnight', desc: 'Cool blue-purple' },
-  { id: 'forest', name: 'Forest', desc: 'Earthy green-brown' },
-  { id: 'dusk', name: 'Dusk', desc: 'Sunset orange-pink' },
-  { id: 'contrast', name: 'Contrast', desc: 'High contrast' },
+  { 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' },
 ] as const;
 
 export function ThemeToggle() {