feat: add global styles and transitions for dark mode support

- Created style.css for base styles and color variables for light and dark themes.
- Added tailwind.css for Tailwind CSS integration and custom theme variables.
- Introduced transitions.css to manage global transitions and reduce motion preferences.
- Updated tsconfig.app.json to include path aliases for easier imports.
- Modified tsconfig.json to set baseUrl and paths for module resolution.
- Added typed-router.d.ts for auto-generated route types.
- Enhanced vite.config.ts with Vue Router plugin, Tailwind CSS integration, and server proxy settings.

frontend/src/components/ui/button/Button.vue

@@ -0,0 +1,26 @@
+<script setup lang="ts">
+  import type { HTMLAttributes } from "vue";
+  import { Primitive, type PrimitiveProps } from "reka-ui";
+  import { cn } from "@/lib/utils";
+  import { type ButtonVariants, buttonVariants } from ".";
+
+  interface Props extends PrimitiveProps {
+    variant?: ButtonVariants["variant"];
+    size?: ButtonVariants["size"];
+    class?: HTMLAttributes["class"];
+  }
+
+  const props = withDefaults(defineProps<Props>(), {
+    as: "button",
+  });
+</script>
+
+<template>
+  <Primitive
+    data-slot="button"
+    :as="as"
+    :as-child="asChild"
+    :class="cn(buttonVariants({ variant, size }), props.class)">
+    <slot />
+  </Primitive>
+</template>