Fix sign-in links and legacy JWT after Periscope rebrand.

/login 404ed from marketing CTAs; redirect to /sign-in and accept pinscope-local tokens plus dual-host CORS so login works on both hostnames.

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

frontend/src/app/(marketing)/contact/nav.tsx

@@ -44,12 +44,12 @@ export function Nav() {
             </Link>
           ) : (
             <>
-              <Link href="/login">
+              <Link href="/sign-in">
                 <Button variant="ghost" size="sm">
                   Sign in
                 </Button>
               </Link>
-              <Link href="/login">
+              <Link href="/sign-up">
                 <Button
                   size="sm"
                   className="bg-blue-600 hover:bg-blue-500 text-white border-0"

frontend/src/app/(marketing)/landing-cta.tsx

@@ -22,12 +22,12 @@ export function NavAuthCluster() {
   }
   return (
     <>
-      <Link href="/login">
+      <Link href="/sign-in">
         <Button variant="ghost" size="sm">
           Sign in
         </Button>
       </Link>
-      <Link href="/login">
+      <Link href="/sign-up">
         <Button
           size="sm"
           className="bg-blue-600 hover:bg-blue-500 text-white border-0"
@@ -41,7 +41,7 @@ export function NavAuthCluster() {
 
 export function PrimaryCta() {
   const { isSignedIn } = useOptionalAuth();
-  const href = isSignedIn ? "/dashboard" : "/login";
+  const href = isSignedIn ? "/dashboard" : "/sign-up";
   const label = isSignedIn ? "Go to Dashboard" : "Start for free";
   return (
     <Link href={href}>
@@ -59,7 +59,7 @@ export function PrimaryCta() {
 export function PricingCta() {
   const { isSignedIn } = useOptionalAuth();
   return (
-    <Link href={isSignedIn ? "/billing" : "/login"}>
+    <Link href={isSignedIn ? "/billing" : "/sign-up"}>
       <Button
         size="sm"
         className="bg-blue-600 hover:bg-blue-500 text-white border-0 gap-1.5"

frontend/src/app/(marketing)/sign-in/page.tsx

@@ -29,7 +29,14 @@ export default function SignInPage() {
       });
       const data = await res.json().catch(() => ({}));
       if (!res.ok) {
-        throw new Error(data.detail || "Sign in failed");
+        const detail = data.detail;
+        const msg =
+          typeof detail === "string"
+            ? detail
+            : Array.isArray(detail)
+              ? detail.map((d: { msg?: string }) => d.msg || JSON.stringify(d)).join("; ")
+              : "Sign in failed";
+        throw new Error(msg);
       }
       storeAuthToken(data.token);
       router.replace("/");

frontend/src/app/(marketing)/sign-up/page.tsx

@@ -35,9 +35,13 @@ export default function SignUpPage() {
       const data = await res.json().catch(() => ({}));
       if (!res.ok) {
         const detail = data.detail;
-        throw new Error(
-          typeof detail === "string" ? detail : "Could not create account",
-        );
+        const msg =
+          typeof detail === "string"
+            ? detail
+            : Array.isArray(detail)
+              ? detail.map((d: { msg?: string }) => d.msg || JSON.stringify(d)).join("; ")
+              : "Could not create account";
+        throw new Error(msg);
       }
       storeAuthToken(data.token);
       router.replace("/");