refactor: simplify frontend theme setup

frontend/src/main.js

@@ -35,10 +35,7 @@ import { useChannelsStore } from '@/features/channels/stores/channelsStore.js';
 import { i18n } from '@/plugins/i18n.js';
 import config from '@/config.js';
 import { createHead } from '@vueuse/head';
-import { applyBranding } from '@/branding/applyBranding.js';
-import { getVuetifyThemeColors } from '@/branding/branding.js';
-
-applyBranding();
+import { socializeTheme } from '@/plugins/theme.js';
 
 const vuetify = createVuetify({
     components: {
@@ -64,10 +61,7 @@ const vuetify = createVuetify({
     theme: {
         defaultTheme: 'socializeLight',
         themes: {
-            socializeLight: {
-                dark: false,
-                colors: getVuetifyThemeColors(),
-            },
+            socializeLight: socializeTheme,
         },
     },
 });