Implement the 010-ui-baseline feature that establishes a modern UI using Tailwind CSS v4 and shadcn/ui-style components for the encounter screen

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

apps/web/src/components/ui/button.tsx

@@ -0,0 +1,38 @@
+import { cva, type VariantProps } from "class-variance-authority";
+import type { ButtonHTMLAttributes } from "react";
+import { cn } from "../../lib/utils";
+
+const buttonVariants = cva(
+	"inline-flex items-center justify-center gap-2 rounded-md text-sm font-medium transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-primary disabled:pointer-events-none disabled:opacity-50",
+	{
+		variants: {
+			variant: {
+				default: "bg-primary text-primary-foreground hover:bg-primary/90",
+				outline:
+					"border border-border bg-transparent hover:bg-card hover:text-foreground",
+				ghost: "hover:bg-card hover:text-foreground",
+			},
+			size: {
+				default: "h-9 px-4 py-2",
+				sm: "h-8 px-3 text-xs",
+				icon: "h-8 w-8",
+			},
+		},
+		defaultVariants: {
+			variant: "default",
+			size: "default",
+		},
+	},
+);
+
+type ButtonProps = ButtonHTMLAttributes<HTMLButtonElement> &
+	VariantProps<typeof buttonVariants>;
+
+export function Button({ className, variant, size, ...props }: ButtonProps) {
+	return (
+		<button
+			className={cn(buttonVariants({ variant, size, className }))}
+			{...props}
+		/>
+	);
+}