Change brand color and logotypes (#18592)

- Add rake task for generating Apple/Android icons and favicons from SVG
- Add rake task for generating PNG icons and logos for e-mails from SVG
- Remove obsolete Microsoft icons and configuration
- Remove PWA shortcut icons

app/serializers/manifest_serializer.rb

@@ -4,7 +4,19 @@ class ManifestSerializer < ActiveModel::Serializer
   include RoutingHelper
   include ActionView::Helpers::TextHelper
 
-  attributes :name, :short_name, :description,
+  ICON_SIZES = %w(
+    36
+    48
+    72
+    96
+    144
+    192
+    256
+    384
+    512
+  ).freeze
+
+  attributes :name, :short_name,
              :icons, :theme_color, :background_color,
              :display, :start_url, :scope,
              :share_target, :shortcuts
@@ -17,22 +29,18 @@ class ManifestSerializer < ActiveModel::Serializer
     object.site_title
   end
 
-  def description
-    strip_tags(object.site_short_description.presence || I18n.t('about.about_mastodon_html'))
-  end
-
   def icons
-    [
+    ICON_SIZES.map do |size|
       {
-        src: '/android-chrome-192x192.png',
-        sizes: '192x192',
+        src: full_pack_url("media/icons/android-chrome-#{size}x#{size}.png"),
+        sizes: "#{size}x#{size}",
         type: 'image/png',
-      },
-    ]
+      }
+    end
   end
 
   def theme_color
-    '#282c37'
+    '#6364FF'
   end
 
   def background_color
@@ -68,37 +76,12 @@ class ManifestSerializer < ActiveModel::Serializer
   def shortcuts
     [
       {
-        name: 'New toot',
+        name: 'Compose new post',
         url: '/web/publish',
-        icons: [
-          {
-            src: '/shortcuts/new-status.png',
-            type: 'image/png',
-            sizes: '192x192',
-          },
-        ],
       },
       {
         name: 'Notifications',
         url: '/web/notifications',
-        icons: [
-          {
-            src: '/shortcuts/notifications.png',
-            type: 'image/png',
-            sizes: '192x192',
-          },
-        ],
-      },
-      {
-        name: 'Direct messages',
-        url: '/web/conversations',
-        icons: [
-          {
-            src: '/shortcuts/direct.png',
-            type: 'image/png',
-            sizes: '192x192',
-          },
-        ],
       },
     ]
   end