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/user-avatar.tsx

@@ -0,0 +1,32 @@
+import { auth } from "@homarr/auth";
+import type { AvatarProps, MantineSize } from "@homarr/ui";
+import { Avatar } from "@homarr/ui";
+
+interface UserAvatarProps {
+  size: MantineSize;
+}
+
+export const UserAvatar = async ({ size }: UserAvatarProps) => {
+  const currentSession = await auth();
+
+  const commonProps = {
+    size,
+    color: "primaryColor",
+  } satisfies Partial<AvatarProps>;
+
+  if (!currentSession) return <Avatar {...commonProps} />;
+  if (currentSession.user.image)
+    return (
+      <Avatar
+        {...commonProps}
+        src={currentSession.user.image}
+        alt={currentSession.user.name!}
+      />
+    );
+
+  return (
+    <Avatar {...commonProps}>
+      {currentSession.user.name!.substring(0, 2).toUpperCase()}
+    </Avatar>
+  );
+};