feat: dynamic frontend tenant dropdown

backend/cmd/server/main.go

@@ -567,6 +567,7 @@ func main() {
 
 	// Signup Routes
 	signup := auth.Group("/signup")
+	signup.Get("/tenants", authHandler.GetActiveTenants)
 	signup.Post("/check-email", authHandler.CheckEmail)
 	signup.Post("/check-login-id", authHandler.CheckLoginID)
 	signup.Post("/send-email-code", authHandler.SendSignupEmailCode)