Switch from SuperTokens to NextAuth.js

BREAKING CHANGE: Replace SuperTokens with NextAuth.js

Why:
- SuperTokens had persistent Traefik routing issues
- SSL certificate not issuing correctly
- Complex infrastructure (separate container)
- NextAuth runs in Next.js app (simpler, no separate service)

Changes:
- Install next-auth, @auth/prisma-adapter, prisma
- Create NextAuth API route: app/api/auth/[...nextauth]/route.ts
- Add Prisma schema for NextAuth tables (users, sessions, accounts)
- Update auth page to use NextAuth signIn()
- Remove all SuperTokens code and dependencies
- Keep same Google OAuth (just simpler integration)

Benefits:
- No separate auth service needed
- No Traefik routing issues
- Sessions stored in Montreal PostgreSQL
- Simpler configuration
- Battle-tested, widely used

All authentication data stays in Montreal!

Co-authored-by: Cursor <cursoragent@cursor.com>

app/auth/page.tsx

@@ -1,38 +1,22 @@
 "use client";
 
-import dynamic from "next/dynamic";
-import { useEffect, useState } from "react";
+import { useSession } from "next-auth/react";
 import { useRouter } from "next/navigation";
-
-// Dynamically import SuperTokens component (client-side only)
-const SuperTokensAuthComponent = dynamic(
-  () => import("@/app/components/SuperTokensAuthComponent"),
-  { ssr: false }
-);
+import { useEffect } from "react";
+import NextAuthComponent from "@/app/components/NextAuthComponent";
 
 export default function AuthPage() {
+  const { data: session, status } = useSession();
   const router = useRouter();
-  const [mounted, setMounted] = useState(false);
 
   useEffect(() => {
-    setMounted(true);
-    
-    // Check if already logged in after a short delay
-    setTimeout(async () => {
-      try {
-        const { doesSessionExist } = await import("supertokens-web-js/recipe/session");
-        const exists = await doesSessionExist();
-        if (exists) {
-          router.push("/marks-account/projects");
-        }
-      } catch (error) {
-        // SuperTokens not initialized yet, continue to show auth page
-        console.log("Session check skipped");
-      }
-    }, 500);
-  }, [router]);
+    // Redirect if already authenticated
+    if (status === "authenticated") {
+      router.push("/marks-account/projects");
+    }
+  }, [status, router]);
 
-  if (!mounted) {
+  if (status === "loading") {
     return (
       <div className="flex min-h-screen items-center justify-center bg-background">
         <div className="text-center">
@@ -43,6 +27,6 @@ export default function AuthPage() {
     );
   }
 
-  return <SuperTokensAuthComponent />;
+  return <NextAuthComponent />;
 }