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/sonner.tsx

@@ -3,9 +3,9 @@
 import {
   CircleCheckIcon,
   InfoIcon,
-  Loader2Icon,
-  OctagonXIcon,
   TriangleAlertIcon,
+  OctagonXIcon,
+  Loader2Icon,
 } from "lucide-react";
 import { useTheme } from "next-themes";
 import { Toaster as Sonner, type ToasterProps } from "sonner";
@@ -32,6 +32,11 @@ const Toaster = ({ ...props }: ToasterProps) => {
           "--border-radius": "var(--radius)",
         } as React.CSSProperties
       }
+      toastOptions={{
+        classNames: {
+          toast: "cn-toast",
+        },
+      }}
       {...props}
     />
   );