first round of review

frontend/app/signup/page.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useState, useEffect, Suspense } from "react";
+import { useState, useEffect, useCallback, Suspense } from "react";
 import { useRouter, useSearchParams } from "next/navigation";
 import { useAuth } from "../auth-context";
 import { api } from "../api";
@@ -20,6 +20,7 @@ function SignupContent() {
   const [inviteValid, setInviteValid] = useState<boolean | null>(null);
   const [inviteError, setInviteError] = useState("");
   const [isCheckingInvite, setIsCheckingInvite] = useState(false);
+  const [isCheckingInitialCode, setIsCheckingInitialCode] = useState(!!initialCode);
   
   const [email, setEmail] = useState("");
   const [password, setPassword] = useState("");
@@ -37,14 +38,7 @@ function SignupContent() {
     }
   }, [user, router]);
 
-  // Check invite code on mount if provided in URL
-  useEffect(() => {
-    if (initialCode) {
-      checkInvite(initialCode);
-    }
-  }, [initialCode]);
-
-  const checkInvite = async (code: string) => {
+  const checkInvite = useCallback(async (code: string) => {
     if (!code.trim()) {
       setInviteValid(null);
       setInviteError("");
@@ -72,7 +66,14 @@ function SignupContent() {
     } finally {
       setIsCheckingInvite(false);
     }
-  };
+  }, []);
+
+  // Check invite code on mount if provided in URL
+  useEffect(() => {
+    if (initialCode) {
+      checkInvite(initialCode).finally(() => setIsCheckingInitialCode(false));
+    }
+  }, [initialCode, checkInvite]);
 
   const handleInviteSubmit = (e: React.FormEvent) => {
     e.preventDefault();
@@ -110,6 +111,21 @@ function SignupContent() {
     return null;
   }
 
+  // Show loading state while checking initial code from URL
+  if (isCheckingInitialCode) {
+    return (
+      <main style={styles.main}>
+        <div style={styles.container}>
+          <div style={styles.card}>
+            <div style={{ textAlign: "center", color: "rgba(255,255,255,0.6)" }}>
+              Checking invite code...
+            </div>
+          </div>
+        </div>
+      </main>
+    );
+  }
+
   // Step 1: Enter invite code
   if (!inviteValid) {
     return (