refactor: migrate from Biome to oxlint/oxfmt, remove contact form

- Replace Biome with oxlint + oxfmt (OXC toolchain) for linting and formatting
- Add .oxlintrc.json and .oxfmtrc.json configuration files
- Update VS Code settings and devcontainer to use oxc-vscode extension
- Remove contact form, Resend email integration, and related server action/schema
- Remove unused UI components (accordion, alert, card, tabs, toggle, etc.)

components/ui/badge.tsx

@@ -1,23 +1,21 @@
-import { Slot } from "@radix-ui/react-slot";
+import { mergeProps } from "@base-ui/react/merge-props";
+import { useRender } from "@base-ui/react/use-render";
 import { cva, type VariantProps } from "class-variance-authority";
-import type * as React from "react";
 
 import { cn } from "@/lib/utils";
 
 const badgeVariants = cva(
-  "inline-flex w-fit shrink-0 items-center justify-center gap-1 overflow-hidden whitespace-nowrap rounded-full border border-transparent px-2 py-0.5 font-medium text-xs transition-[color,box-shadow] focus-visible:border-ring focus-visible:ring-[3px] focus-visible:ring-ring/50 aria-invalid:border-destructive aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 [&>svg]:pointer-events-none [&>svg]:size-3",
+  "group/badge focus-visible:border-ring focus-visible:ring-ring/50 aria-invalid:border-destructive aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 inline-flex h-5 w-fit shrink-0 items-center justify-center gap-1 overflow-hidden rounded-4xl border border-transparent px-2 py-0.5 text-xs font-medium whitespace-nowrap transition-all focus-visible:ring-[3px] has-data-[icon=inline-end]:pr-1.5 has-data-[icon=inline-start]:pl-1.5 [&>svg]:pointer-events-none [&>svg]:size-3!",
   {
     variants: {
       variant: {
-        default: "bg-primary text-primary-foreground [a&]:hover:bg-primary/90",
-        secondary:
-          "bg-secondary text-secondary-foreground [a&]:hover:bg-secondary/90",
+        default: "bg-primary text-primary-foreground [a]:hover:bg-primary/80",
+        secondary: "bg-secondary text-secondary-foreground [a]:hover:bg-secondary/80",
         destructive:
-          "bg-destructive text-white focus-visible:ring-destructive/20 dark:bg-destructive/60 dark:focus-visible:ring-destructive/40 [a&]:hover:bg-destructive/90",
-        outline:
-          "border-border text-foreground [a&]:hover:bg-accent [a&]:hover:text-accent-foreground",
-        ghost: "[a&]:hover:bg-accent [a&]:hover:text-accent-foreground",
-        link: "text-primary underline-offset-4 [a&]:hover:underline",
+          "bg-destructive/10 text-destructive focus-visible:ring-destructive/20 dark:bg-destructive/20 dark:focus-visible:ring-destructive/40 [a]:hover:bg-destructive/20",
+        outline: "border-border text-foreground [a]:hover:bg-muted [a]:hover:text-muted-foreground",
+        ghost: "hover:bg-muted hover:text-muted-foreground dark:hover:bg-muted/50",
+        link: "text-primary underline-offset-4 hover:underline",
       },
     },
     defaultVariants: {
@@ -29,20 +27,23 @@ const badgeVariants = cva(
 function Badge({
   className,
   variant = "default",
-  asChild = false,
+  render,
   ...props
-}: React.ComponentProps<"span"> &
-  VariantProps<typeof badgeVariants> & { asChild?: boolean }) {
-  const Comp = asChild ? Slot : "span";
-
-  return (
-    <Comp
-      data-slot="badge"
-      data-variant={variant}
-      className={cn(badgeVariants({ variant }), className)}
-      {...props}
-    />
-  );
+}: useRender.ComponentProps<"span"> & VariantProps<typeof badgeVariants>) {
+  return useRender({
+    defaultTagName: "span",
+    props: mergeProps<"span">(
+      {
+        className: cn(badgeVariants({ variant }), className),
+      },
+      props,
+    ),
+    render,
+    state: {
+      slot: "badge",
+      variant,
+    },
+  });
 }
 
 export { Badge, badgeVariants };