feat: add app shell with top bar, view routing, and board factory

src/components/layout/AppShell.tsx

@@ -0,0 +1,18 @@
+import type { ReactNode } from "react";
+import { TooltipProvider } from "@/components/ui/tooltip";
+import { TopBar } from "@/components/layout/TopBar";
+
+interface AppShellProps {
+  children: ReactNode;
+}
+
+export function AppShell({ children }: AppShellProps) {
+  return (
+    <TooltipProvider>
+      <div className="flex h-screen flex-col bg-pylon-bg">
+        <TopBar />
+        <main className="flex-1 overflow-hidden">{children}</main>
+      </div>
+    </TooltipProvider>
+  );
+}