Redirect to production for login when on local dev

OAuth PKCE state is origin-scoped — initiating from 127.0.0.1
and receiving callback on coffee.apoena.dev breaks the flow.
From local dev, redirect to production login with handle pre-filled.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/views/LoginView.vue

@@ -40,14 +40,24 @@
 
 <script setup lang="ts">
 import { ref } from 'vue'
+import { useRoute } from 'vue-router'
 import { useAuthStore } from '@/stores/auth'
 
 const auth = useAuthStore()
-const handle = ref('')
+const route = useRoute()
+const handle = ref((route.query.handle as string) ?? '')
 const loading = ref(false)
 const error = ref('')
 
+const PROD_URL = 'https://coffee.apoena.dev'
+const isLocalDev = window.location.origin !== PROD_URL
+
 async function handleSubmit() {
+  // OAuth state is scoped to the initiating origin — must start from production
+  if (isLocalDev) {
+    window.location.href = `${PROD_URL}/login?handle=${encodeURIComponent(handle.value.trim())}`
+    return
+  }
   loading.value = true
   error.value = ''
   try {