feat: add widget preview pages (#9)

* feat: add widget definition system

* fix: wrong typecheck command in turbo generator

* chore: fix formatting

* feat: add widget preview page

* chore: fix formatting and type errors

* chore: fix from widget edit modal and remove some never casts

* chore: address pull request feedback

apps/nextjs/src/components/layout/header.tsx

@@ -0,0 +1,30 @@
+import Link from "next/link";
+
+import { AppShellHeader, Group, UnstyledButton } from "@homarr/ui";
+
+import { ClientBurger } from "./header/burger";
+import { DesktopSearchInput, MobileSearchButton } from "./header/search";
+import { ClientSpotlight } from "./header/spotlight";
+import { UserButton } from "./header/user";
+import { LogoWithTitle } from "./logo";
+
+export const MainHeader = () => {
+  return (
+    <AppShellHeader>
+      <Group h="100%" gap="xl" px="md" justify="apart" wrap="nowrap">
+        <Group h="100%" align="center" style={{ flex: 1 }} wrap="nowrap">
+          <ClientBurger />
+          <UnstyledButton component={Link} href="/">
+            <LogoWithTitle size="md" />
+          </UnstyledButton>
+        </Group>
+        <DesktopSearchInput />
+        <Group h="100%" align="center" justify="end" style={{ flex: 1 }}>
+          <MobileSearchButton />
+          <UserButton />
+        </Group>
+      </Group>
+      <ClientSpotlight />
+    </AppShellHeader>
+  );
+};