signup dialog changes

- send empty or invalid emails to the standard fxa signup page
- show the signup dialog when file too big and not logged in

app/ui/signupDialog.js

@@ -4,6 +4,9 @@ const { bytes } = require('../utils');
 
 module.exports = function() {
   return function(state, emit, close) {
+    setTimeout(function() {
+      document.getElementById('email-input').focus();
+    });
     return html`
     <div class="flex flex-col p-4">
       <p class="p-8">
@@ -39,18 +42,20 @@ module.exports = function() {
       </button>
     </div>`;
 
+    function emailish(str) {
+      if (!str) {
+        return false;
+      }
+      // just check if it's the right shape
+      const a = str.split('@');
+      return a.length === 2 && a.every(s => s.length > 0);
+    }
+
     function submitEmail(event) {
       event.preventDefault();
       const el = document.getElementById('email-input');
       const email = el.value;
-      if (email) {
-        // just check if it's the right shape
-        const a = email.split('@');
-        if (a.length === 2 && a.every(s => s.length > 0)) {
-          return emit('login', email);
-        }
-      }
-      el.value = '';
+      emit('login', emailish(email) ? email : null);
     }
   };
 };