fix(login): fix captcha headers for manual login (#4025)

* fix(signup): fix turnstile key loading

* fix(login): fix captcha header passing

* Catch user already exists, remove login form captcha

---------

Co-authored-by: Theodore Li <theo@sim.ai>

Author: TheodoreSpeaks

apps/sim/app/(auth)/signup/signup-form.tsx

@@ -270,10 +270,8 @@ function SignupFormContent({
           name: sanitizedName,
         },
         {
-          fetchOptions: {
-            headers: {
-              ...(token ? { 'x-captcha-response': token } : {}),
-            },
+          headers: {
+            ...(token ? { 'x-captcha-response': token } : {}),
           },
           onError: (ctx) => {
             logger.error('Signup error:', ctx.error)
@@ -282,10 +280,7 @@ function SignupFormContent({
             let errorCode = 'unknown'
             if (ctx.error.code?.includes('USER_ALREADY_EXISTS')) {
               errorCode = 'user_already_exists'
-              errorMessage.push(
-                'An account with this email already exists. Please sign in instead.'
-              )
-              setEmailError(errorMessage[0])
+              setEmailError('An account with this email already exists. Please sign in instead.')
             } else if (
               ctx.error.code?.includes('BAD_REQUEST') ||
               ctx.error.message?.includes('Email and password sign up is not enabled')