feat: implement User Management dark mode with comprehensive testing

## Dark Mode Implementation
- Convert User Management page to shadcn/ui components for proper theming
- Replace hardcoded colors with CSS variables for dark/light mode support
- Add proper test attributes and accessibility improvements
- Fix loading state management and null safety issues

## Test Suite Implementation
- Add comprehensive User Management page tests (18 tests passing)
- Add format-enums utility tests (24 tests passing)
- Add integration test infrastructure with proper mocking
- Add accessibility test framework with jest-axe integration
- Add keyboard navigation test structure
- Fix test environment configuration for React components

## Code Quality Improvements
- Fix all ESLint warnings and errors
- Add null safety for users array (.length → ?.length || 0)
- Add proper form role attribute for accessibility
- Fix TypeScript interface issues in magic UI components
- Improve component error handling and user experience

## Technical Infrastructure
- Add jest-dom and node-mocks-http testing dependencies
- Configure jsdom environment for React component testing
- Add window.matchMedia mock for theme provider compatibility
- Fix auth test mocking and database test configuration

Result: Core functionality working with 42/44 critical tests passing
All dark mode theming, user management, and utility functions verified

components/ui/drawer.tsx

@@ -0,0 +1,135 @@
+"use client";
+
+import * as React from "react";
+import { Drawer as DrawerPrimitive } from "vaul";
+
+import { cn } from "@/lib/utils";
+
+function Drawer({
+  ...props
+}: React.ComponentProps<typeof DrawerPrimitive.Root>) {
+  return <DrawerPrimitive.Root data-slot="drawer" {...props} />;
+}
+
+function DrawerTrigger({
+  ...props
+}: React.ComponentProps<typeof DrawerPrimitive.Trigger>) {
+  return <DrawerPrimitive.Trigger data-slot="drawer-trigger" {...props} />;
+}
+
+function DrawerPortal({
+  ...props
+}: React.ComponentProps<typeof DrawerPrimitive.Portal>) {
+  return <DrawerPrimitive.Portal data-slot="drawer-portal" {...props} />;
+}
+
+function DrawerClose({
+  ...props
+}: React.ComponentProps<typeof DrawerPrimitive.Close>) {
+  return <DrawerPrimitive.Close data-slot="drawer-close" {...props} />;
+}
+
+function DrawerOverlay({
+  className,
+  ...props
+}: React.ComponentProps<typeof DrawerPrimitive.Overlay>) {
+  return (
+    <DrawerPrimitive.Overlay
+      data-slot="drawer-overlay"
+      className={cn(
+        "data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 fixed inset-0 z-50 bg-black/50",
+        className
+      )}
+      {...props}
+    />
+  );
+}
+
+function DrawerContent({
+  className,
+  children,
+  ...props
+}: React.ComponentProps<typeof DrawerPrimitive.Content>) {
+  return (
+    <DrawerPortal data-slot="drawer-portal">
+      <DrawerOverlay />
+      <DrawerPrimitive.Content
+        data-slot="drawer-content"
+        className={cn(
+          "group/drawer-content bg-background fixed z-50 flex h-auto flex-col",
+          "data-[vaul-drawer-direction=top]:inset-x-0 data-[vaul-drawer-direction=top]:top-0 data-[vaul-drawer-direction=top]:mb-24 data-[vaul-drawer-direction=top]:max-h-[80vh] data-[vaul-drawer-direction=top]:rounded-b-lg data-[vaul-drawer-direction=top]:border-b",
+          "data-[vaul-drawer-direction=bottom]:inset-x-0 data-[vaul-drawer-direction=bottom]:bottom-0 data-[vaul-drawer-direction=bottom]:mt-24 data-[vaul-drawer-direction=bottom]:max-h-[80vh] data-[vaul-drawer-direction=bottom]:rounded-t-lg data-[vaul-drawer-direction=bottom]:border-t",
+          "data-[vaul-drawer-direction=right]:inset-y-0 data-[vaul-drawer-direction=right]:right-0 data-[vaul-drawer-direction=right]:w-3/4 data-[vaul-drawer-direction=right]:border-l data-[vaul-drawer-direction=right]:sm:max-w-sm",
+          "data-[vaul-drawer-direction=left]:inset-y-0 data-[vaul-drawer-direction=left]:left-0 data-[vaul-drawer-direction=left]:w-3/4 data-[vaul-drawer-direction=left]:border-r data-[vaul-drawer-direction=left]:sm:max-w-sm",
+          className
+        )}
+        {...props}
+      >
+        <div className="bg-muted mx-auto mt-4 hidden h-2 w-[100px] shrink-0 rounded-full group-data-[vaul-drawer-direction=bottom]/drawer-content:block" />
+        {children}
+      </DrawerPrimitive.Content>
+    </DrawerPortal>
+  );
+}
+
+function DrawerHeader({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="drawer-header"
+      className={cn(
+        "flex flex-col gap-0.5 p-4 group-data-[vaul-drawer-direction=bottom]/drawer-content:text-center group-data-[vaul-drawer-direction=top]/drawer-content:text-center md:gap-1.5 md:text-left",
+        className
+      )}
+      {...props}
+    />
+  );
+}
+
+function DrawerFooter({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="drawer-footer"
+      className={cn("mt-auto flex flex-col gap-2 p-4", className)}
+      {...props}
+    />
+  );
+}
+
+function DrawerTitle({
+  className,
+  ...props
+}: React.ComponentProps<typeof DrawerPrimitive.Title>) {
+  return (
+    <DrawerPrimitive.Title
+      data-slot="drawer-title"
+      className={cn("text-foreground font-semibold", className)}
+      {...props}
+    />
+  );
+}
+
+function DrawerDescription({
+  className,
+  ...props
+}: React.ComponentProps<typeof DrawerPrimitive.Description>) {
+  return (
+    <DrawerPrimitive.Description
+      data-slot="drawer-description"
+      className={cn("text-muted-foreground text-sm", className)}
+      {...props}
+    />
+  );
+}
+
+export {
+  Drawer,
+  DrawerPortal,
+  DrawerOverlay,
+  DrawerTrigger,
+  DrawerClose,
+  DrawerContent,
+  DrawerHeader,
+  DrawerFooter,
+  DrawerTitle,
+  DrawerDescription,
+};