trim settings-site to match stripped bot

- delete public/js/notifications.js (521 LOC)
- remove notifications/patterns/surge/chat/priority/bosscord/accountinfo/threads UI sections
- remove 3 /api/notifications/* proxy routes from server.js
- untrack settings-site backup files from git
- ~926 LOC removed from settings-site

settings-site/public/js/router.js

@@ -10,7 +10,6 @@
     '/behavior': 's-behavior',
     '/threads': 's-threads',
     '/pins': 's-pins',
-    '/notifications': 's-notifications',
     '/logging': 's-logging',
     '/automation': 's-automation',
     '/appearance': 's-appearance',