feat: Implement theme toggling and enhance dashboard component theming

This commit introduces a theme toggle functionality in the application header
and improves the visual consistency of dashboard components across different
color schemes.

- Added light/dark mode toggle to  using Mantine's .
- Ensured all  components in  have visible borders in both light and dark modes by adding the  prop.
- Made  colors in  theme-aware, dynamically adjusting their background color based on the active color scheme.

Additionally, this commit includes a large refactoring operation, moving various
component files from  to  and updating
their references.

src/routes/admin/route.tsx

@@ -30,7 +30,6 @@ import {
 	useNavigate,
 } from "@tanstack/react-router";
 import { useSnapshot } from "valtio";
-import { ColorSchemeToggle } from "@/components/ColorSchemeToggle";
 import { protectedRouteMiddleware } from "@/middleware/authMiddleware";
 import { authClient } from "@/utils/auth-client";
 import { authStore } from "../../store/auth";
@@ -155,7 +154,6 @@ function DashboardLayout() {
 					</Group>
 
 					<Group gap="md">
-						<ColorSchemeToggle />
 
 						<Menu
 							shadow="md"