fix: UI improvements

.gitignore

client/components/admin/admin-system.vue

client/components/common/duration-picker.vue

client/components/common/nav-header.vue

client/components/common/page-delete.vue

client/components/common/search-results.vue

client/components/editor.vue

client/components/editor/editor-markdown.vue

client/components/editor/editor-modal-media.vue

client/components/editor/editor-modal-properties.vue

client/components/history.vue

client/themes/default/components/page.vue

client/themes/default/scss/app.scss

server/views/legacy/master.pug

server/views/master.pug

server/views/setup.pug