Frontend revamp: Animal Crossing × Claude design with shadcn components

- New palette: deep nook green sidebar, sage user bubbles, warm cream answer cards
- shadcn-style UI primitives: Button (CVA variants), Textarea, Input, Badge, Table
- cn() utility (clsx + tailwind-merge)
- lucide-react icons throughout (no more text-only buttons)
- Simba mode: custom CSS toggle switch
- Send button: circular amber button with arrow icon
- AnswerBubble: amber gradient accent bar, loading dots animation
- QuestionBubble: sage green pill with rounded-3xl
- ToolBubble: centered leaf-green badge pill
- ConversationList: active item highlighting, proper selectedId prop
- Sidebar: collapsible with PanelLeftClose/Open icons, icon-only collapsed state
- LoginScreen: decorative background blobs, refined rounded card
- AdminPanel: proper icon buttons, leaf-green save confirmation
- Fonts: Playfair Display (brand) + Nunito 800 weight added

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

raggr-frontend/src/components/ui/textarea.tsx

@@ -0,0 +1,19 @@
+import { cn } from "../../lib/utils";
+
+export interface TextareaProps
+  extends React.TextareaHTMLAttributes<HTMLTextAreaElement> {}
+
+export const Textarea = ({ className, ...props }: TextareaProps) => {
+  return (
+    <textarea
+      className={cn(
+        "flex w-full resize-none rounded-xl border-0 bg-transparent px-3 py-2.5",
+        "text-sm text-charcoal placeholder:text-warm-gray/50",
+        "focus:outline-none",
+        "disabled:cursor-not-allowed disabled:opacity-50",
+        className,
+      )}
+      {...props}
+    />
+  );
+};