fix(auth): make signup path obvious for first-time users

The /auth page was titled 'Welcome back' which made first-time
visitors think they needed an existing account. Google OAuth
already creates accounts on first sign-in, so this was a copy
problem, not a missing flow.

- Default copy is now neutral ('Sign in or sign up'); explicitly
  notes that an account is auto-created on first sign-in.
- All marketing 'Get started' / 'Start free' CTAs now link to
  /auth?new=1 which switches the page to 'Create your account'
  copy. Plain 'Log in' links keep the neutral default.

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

app/components/NextAuthComponent.tsx

@@ -60,11 +60,21 @@ function NextAuthForm() {
     }
   };
 
+  // Detect new-vs-returning purely from local search params; we
+  // don't have a session at this render path, but the homepage
+  // sends "Get started" links with `?new=1` and "Sign in" links
+  // without it. Fall back to neutral copy that works for both.
+  const isNewUser = searchParams.get("new") === "1";
+  const title = isNewUser ? "Create your account" : "Sign in or sign up";
+  const subtitle = isNewUser
+    ? "Continue with Google to set up your Vibn workspace."
+    : "Continue with Google. New here? An account is created automatically on first sign-in.";
+
   return (
     <div className="justine-auth-inner">
       <div className="justine-auth-card">
-        <h1 className="justine-auth-title f">Welcome back</h1>
+        <h1 className="justine-auth-title f">{title}</h1>
-        <p className="justine-auth-sub">Sign in with Google to open your workspace.</p>
+        <p className="justine-auth-sub">{subtitle}</p>
 
         {errorHint && (
           <div

marketing/components/cta.tsx

@@ -12,7 +12,7 @@ export function CTA() {
           {homepage.finalCTA.title}
         </h2>
         <div className="flex flex-col sm:flex-row gap-4 pt-4">
-          <Link href="/auth">
+          <Link href="/auth?new=1">
             <Button size="lg" className="h-12 px-8 text-base">
               <Sparkles className="mr-2 h-5 w-5" />
               {homepage.finalCTA.cta.primary}

marketing/components/footer.tsx

@@ -9,7 +9,7 @@ const links = {
     { label: "How It Works", href: "/#how-it-works" },
     { label: "Pricing",     href: "/#pricing" },
     { label: "Sign In",     href: "/auth" },
-    { label: "Get Started", href: "/auth" },
+    { label: "Get Started", href: "/auth?new=1" },
   ],
   resources: [
     { label: "GitHub",      href: "https://github.com/MawkOne/viben", external: true },

marketing/components/hero.tsx

@@ -21,7 +21,7 @@ export function Hero() {
         
         {/* CTAs */}
         <div className="flex flex-col sm:flex-row gap-4 mt-4">
-          <Link href="/auth">
+          <Link href="/auth?new=1">
             <Button size="lg" className="h-12 px-8 text-base">
               <Sparkles className="mr-2 h-5 w-5" />
               {homepage.hero.cta.primary}

marketing/components/justine/JustineHomePage.tsx

@@ -170,7 +170,7 @@ export function JustineHomePage() {
             marginTop: 52,
           }}
         >
-          <Link href="/auth">
+          <Link href="/auth?new=1">
             <button type="button" className="btn-ink-lg">
               Start free — no code needed
             </button>
@@ -505,7 +505,7 @@ export function JustineHomePage() {
           <p style={{ fontSize: 16, color: "var(--mid)", lineHeight: 1.75, marginBottom: 38 }}>
             Thousands of ideas never make it past a spreadsheet. Yours doesn&apos;t have to be one of them.
           </p>
-          <Link href="/auth">
+          <Link href="/auth?new=1">
             <button type="button" className="btn-ink-lg" style={{ marginBottom: 16 }}>
               Build my product — free
             </button>

marketing/components/justine/JustineNav.tsx

@@ -66,7 +66,7 @@ export function JustineNav() {
           <Link href="/auth" style={{ fontSize: 14, color: "#6366F1", fontWeight: 600, textDecoration: "none" }}>
             Log in
           </Link>
-          <Link href="/auth">
+          <Link href="/auth?new=1">
             <button type="button" className="btn-ink">
               Get started free
             </button>
@@ -103,7 +103,7 @@ export function JustineNav() {
           Log in
         </Link>
         <div className="mobile-menu-cta">
-          <Link href="/auth" onClick={close} style={{ display: "block", width: "100%" }}>
+          <Link href="/auth?new=1" onClick={close} style={{ display: "block", width: "100%" }}>
             <button type="button" className="btn-ink-lg" style={{ width: "100%" }}>
               Get started free
             </button>