feat(mastodon): Add support for server announcements

Implemented a new 'Announcements' buffer to view instance-wide news. Features include:

- New buffer and UI panel for announcements.

- Support for templates and rendering of announcement content.

- 'Dismiss' functionality (mapped to Enter/Return) to mark announcements as read.

- Integrated into account settings for buffer management.

src/controller/mastodon/handler.py

@@ -92,6 +92,8 @@ class Handler(object):
                 pub.sendMessage("createBuffer", buffer_type="UserBuffer", session_type=session.type, buffer_title=_("Blocked users"), parent_tab=root_position, start=False, kwargs=dict(parent=controller.view.nb, compose_func="compose_user", function="blocks", name="blocked", sessionObject=session, account=name))
             elif i == 'notifications':
                 pub.sendMessage("createBuffer", buffer_type="NotificationsBuffer", session_type=session.type, buffer_title=_("Notifications"), parent_tab=root_position, start=False, kwargs=dict(parent=controller.view.nb, compose_func="compose_notification", function="notifications", name="notifications", sessionObject=session, account=name))
+            elif i == 'announcements':
+                pub.sendMessage("createBuffer", buffer_type="AnnouncementsBuffer", session_type=session.type, buffer_title=_("Announcements"), parent_tab=root_position, start=False, kwargs=dict(parent=controller.view.nb, function="announcements", name="announcements", sessionObject=session, account=name, sound="new_event.ogg"))
         pub.sendMessage("createBuffer", buffer_type="EmptyBuffer", session_type="base", buffer_title=_("Timelines"), parent_tab=root_position, start=False, kwargs=dict(parent=controller.view.nb, name="timelines", account=name))
         timelines_position =controller.view.search("timelines", name)
         for i in session.settings["other_buffers"]["timelines"]:

src/controller/mastodon/settings.py

@@ -204,6 +204,7 @@ class accountSettingsController(globalSettingsController):
         all_buffers['blocked']=_("Blocked users")
         all_buffers['muted']=_("Muted users")
         all_buffers['notifications']=_("Notifications")
+        all_buffers['announcements']=_("Announcements")
         list_buffers = []
         hidden_buffers=[]
         all_buffers_keys = list(all_buffers.keys())