feat(18-05): add public profile page and setup visibility toggle

- Create public profile page at /users/$userId with avatar, name, bio, setups
- Create PublicSetupCard component for profile page setup listing
- Add isPublic toggle button on setup detail page
- Add Public badge to SetupCard in list view
- Update useSetups hook with isPublic field on interfaces

src/client/routes/users/$userId.tsx

@@ -0,0 +1,102 @@
+import { createFileRoute, Link } from "@tanstack/react-router";
+import { PublicSetupCard } from "../../components/PublicSetupCard";
+import { usePublicProfile } from "../../hooks/useProfile";
+
+export const Route = createFileRoute("/users/$userId")({
+	component: PublicProfilePage,
+});
+
+function PublicProfilePage() {
+	const { userId } = Route.useParams();
+	const numericId = Number(userId);
+	const { data: profile, isLoading, isError } = usePublicProfile(numericId);
+
+	if (isLoading) {
+		return (
+			<div className="max-w-3xl mx-auto px-4 sm:px-6 lg:px-8 py-10">
+				<div className="animate-pulse space-y-6">
+					<div className="flex items-center gap-4">
+						<div className="w-20 h-20 rounded-full bg-gray-200" />
+						<div className="space-y-2">
+							<div className="h-6 bg-gray-200 rounded w-40" />
+							<div className="h-4 bg-gray-200 rounded w-64" />
+						</div>
+					</div>
+					<div className="h-4 bg-gray-200 rounded w-24" />
+					<div className="grid grid-cols-1 md:grid-cols-2 gap-4">
+						<div className="h-24 bg-gray-200 rounded-xl" />
+						<div className="h-24 bg-gray-200 rounded-xl" />
+					</div>
+				</div>
+			</div>
+		);
+	}
+
+	if (isError || !profile) {
+		return (
+			<div className="max-w-3xl mx-auto px-4 sm:px-6 lg:px-8 py-16 text-center">
+				<p className="text-gray-500">User not found.</p>
+				<Link
+					to="/"
+					className="text-sm text-gray-500 hover:text-gray-700 mt-4 inline-block"
+				>
+					&larr; Back to home
+				</Link>
+			</div>
+		);
+	}
+
+	const displayName = profile.displayName || `User #${profile.id}`;
+
+	return (
+		<div className="max-w-3xl mx-auto px-4 sm:px-6 lg:px-8 py-10">
+			{/* Profile header */}
+			<div className="flex items-center gap-5 mb-8">
+				{profile.avatarUrl ? (
+					<img
+						src={`/uploads/${profile.avatarUrl}`}
+						alt={displayName}
+						className="w-20 h-20 rounded-full object-cover"
+					/>
+				) : (
+					<div className="w-20 h-20 rounded-full bg-gray-100 flex items-center justify-center">
+						<svg
+							className="w-10 h-10 text-gray-300"
+							fill="none"
+							stroke="currentColor"
+							viewBox="0 0 24 24"
+							strokeWidth={1.5}
+						>
+							<path d="M20 21v-2a4 4 0 0 0-4-4H8a4 4 0 0 0-4 4v2" />
+							<circle cx="12" cy="7" r="4" />
+						</svg>
+					</div>
+				)}
+				<div>
+					<h1 className="text-xl font-semibold text-gray-900">{displayName}</h1>
+					{profile.bio && (
+						<p className="text-sm text-gray-500 mt-1 max-w-md">{profile.bio}</p>
+					)}
+				</div>
+			</div>
+
+			{/* Public setups */}
+			<div>
+				<h2 className="text-base font-medium text-gray-900 mb-4">
+					Public Setups
+				</h2>
+				{profile.setups.length === 0 ? (
+					<p className="text-sm text-gray-400 py-8 text-center">
+						No public setups yet
+					</p>
+				) : (
+					<div className="grid grid-cols-1 md:grid-cols-2 gap-4">
+						{profile.setups.map((setup) => (
+							<PublicSetupCard key={setup.id} setup={setup} />
+						))}
+					</div>
+				)}
+			</div>
+		</div>
+	);
+}