backend: login and logout

backend/views/social/success.pug

@@ -0,0 +1,17 @@
+doctype html
+html
+    body
+        script.
+            window.opener.postMessage({
+              type: 'oauth_login',
+              user: {
+                id: '#{_id}',
+                token: '#{token}',
+                name: '#{name}',
+                photo: '#{photo}',
+                role: '#{role}',
+              }
+            }, '*');
+
+            window.close();
+

backend/views/social/vk_error.pug

@@ -0,0 +1,13 @@
+doctype html
+html
+    head
+        title Ошибка авторизации
+        link(rel='stylesheet', href='/stylesheets/social/vk.css')
+
+    body
+        block content
+            div#message
+                div.bg
+                    h1=heading
+                    div=reason
+                    button(onclick='window.close()')=button