DEV: Add showLogin action to post menu buttons and prevent text selection (#30500)

This commit adds `showLogin` as an available action to the post menu buttons. They can use this action to show the login form when there is no user logged in.

It also adds a small CSS tweak to prevent the content from the post menu to being user selectable. This was causing small UX issues in touch devices.

app/assets/javascripts/discourse/app/components/post/menu.gjs

@@ -113,6 +113,7 @@ export default class PostMenu extends Component {
       showDeleteTopicModal: this.showDeleteTopicModal,
       showFlags: this.args.showFlags,
       showMoreActions: this.showMoreActions,
+      showLogin: this.args.showLogin,
       toggleReplies: this.args.toggleReplies,
       toggleWhoLiked: this.toggleWhoLiked,
       toggleWhoRead: this.toggleWhoRead,

app/assets/stylesheets/common/base/topic-post.scss

@@ -314,6 +314,8 @@ nav.post-controls {
 
   color: var(--primary-low-mid);
 
+  @include user-select(none);
+
   .actions {
     display: inline-flex;
     text-align: right;