feat(ui): Add UI library (#900)

* feat: scaffold UI library

* Update packages/ui/src/components/theme-provider.tsx

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* add lock file

* lint/formatting fixes

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

packages/ui/src/index.ts

@@ -0,0 +1,13 @@
+export { ThemeProvider, useTheme } from "@/components/theme-provider";
+export * from "@/components/ui/badge.tsx";
+export * from "@/components/ui/sidebar";
+export { AppSidebar } from "./lib/components/index.ts";
+
+// Types
+export type {
+  AppSidebarProps,
+  NavLink,
+  SidebarSectionProps,
+} from "./lib/components/Sidebar/AppSidebar.tsx";
+
+export { ThemeToggle } from "./lib/components/theme-toggle.tsx";