feat(ui): overhaul frontend with IMPHNEN visual identity

- Update CSS foundation: HSL→oklch color tokens, Poppins font, new utilities
- Replace Three.js sakura particles with CSS glow orbs
- Rebrand Header with IMPHNEN logo and gradient text
- Update all UI components (Button, Card, Badge, Input, Select, Tabs, Toast)
- Apply IMPHNEN design patterns (glass, gradient, grid) to layout
- Remove all hardcoded #7EC8E3/#FFB7C5/#FCA5A5 references
- Standardize rounded-xl across all components
- Replace emoji toasts with Lucide icons

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

services/frontend/src/shared/ui/tabs.tsx

@@ -26,7 +26,7 @@ export function TabsTrigger({
   return (
     <TabsPrimitive.Trigger
       className={cn(
-        "inline-flex items-center justify-center whitespace-nowrap rounded-lg px-3 py-1.5 text-sm font-medium transition-all focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring disabled:pointer-events-none disabled:opacity-50 data-[state=active]:bg-primary-soft data-[state=active]:text-foreground data-[state=active]:shadow-sm",
+        "inline-flex items-center justify-center whitespace-nowrap rounded-lg px-3 py-1.5 text-sm font-medium transition-all focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring disabled:pointer-events-none disabled:opacity-50 data-[state=active]:bg-background data-[state=active]:text-foreground data-[state=active]:shadow-sm",
         className,
       )}
       {...props}