use one Archive instance for state.archive

app/ui/archiveTile.js

@@ -345,6 +345,7 @@ module.exports.empty = function(state, emit) {
       />
       <label
         for="file-upload"
+        role="button"
         class="rounded bg-blue hover\:bg-blue-dark focus\:bg-blue-darker cursor-pointer text-center text-white py-2 px-6 h-12 mt-4 flex flex-no-shrink items-center justify-center font-semibold"
         title="${state.translate('addFilesButton')}"
       >

app/ui/home.js

@@ -11,14 +11,14 @@ module.exports = function(state, emit) {
   let left = '';
   if (state.uploading) {
     left = archiveTile.uploading(state, emit);
-  } else if (state.archive) {
+  } else if (state.archive.numFiles > 0) {
     left = archiveTile.wip(state, emit);
   } else {
     left = archiveTile.empty(state, emit);
   }
   archives.reverse();
   const right =
-    archives.length < 1
+    archives.length === 0
       ? intro(state)
       : list(
           archives,