Got it running with sentry and plausible and stuff. Auth seems good

src/app/signin/page.tsx

@@ -0,0 +1,71 @@
+'use client';
+
+import { useAuthActions } from '@convex-dev/auth/react';
+import { useRouter } from 'next/navigation';
+import { useState } from 'react';
+
+export default function SignIn() {
+  const { signIn } = useAuthActions();
+  const [flow, setFlow] = useState<'signIn' | 'signUp'>('signIn');
+  const [error, setError] = useState<string | null>(null);
+  const router = useRouter();
+  return (
+    <div className='flex flex-col gap-8 w-96 mx-auto h-screen justify-center items-center'>
+      <p>Log in to see the numbers</p>
+      <form
+        className='flex flex-col gap-2'
+        onSubmit={(e) => {
+          e.preventDefault();
+          const formData = new FormData(e.target as HTMLFormElement);
+          formData.set('flow', flow);
+          void signIn('password', formData)
+            .catch((error) => {
+              setError(error.message);
+            })
+            .then(() => {
+              router.push('/');
+            });
+        }}
+      >
+        <input
+          className='bg-background text-foreground rounded-md p-2 border-2 border-slate-200 dark:border-slate-800'
+          type='email'
+          name='email'
+          placeholder='Email'
+        />
+        <input
+          className='bg-background text-foreground rounded-md p-2 border-2 border-slate-200 dark:border-slate-800'
+          type='password'
+          name='password'
+          placeholder='Password'
+        />
+        <button
+          className='bg-foreground text-background rounded-md'
+          type='submit'
+        >
+          {flow === 'signIn' ? 'Sign in' : 'Sign up'}
+        </button>
+        <div className='flex flex-row gap-2'>
+          <span>
+            {flow === 'signIn'
+              ? "Don't have an account?"
+              : 'Already have an account?'}
+          </span>
+          <span
+            className='text-foreground underline hover:no-underline cursor-pointer'
+            onClick={() => setFlow(flow === 'signIn' ? 'signUp' : 'signIn')}
+          >
+            {flow === 'signIn' ? 'Sign up instead' : 'Sign in instead'}
+          </span>
+        </div>
+        {error && (
+          <div className='bg-red-500/20 border-2 border-red-500/50 rounded-md p-2'>
+            <p className='text-foreground font-mono text-xs'>
+              Error signing in: {error}
+            </p>
+          </div>
+        )}
+      </form>
+    </div>
+  );
+}