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/providers.tsx

@@ -2,14 +2,11 @@
 
 import { ThemeProvider } from "next-themes";
 
+import { TooltipProvider } from "@/components/ui/tooltip";
+
 const Providers = ({ children }: { children: React.ReactNode }) => (
-  <ThemeProvider
-    attribute="class"
-    defaultTheme="system"
-    enableSystem
-    disableTransitionOnChange
-  >
-    {children}
+  <ThemeProvider attribute="class" defaultTheme="system" enableSystem disableTransitionOnChange>
+    <TooltipProvider>{children}</TooltipProvider>
   </ThemeProvider>
 );