fix: pagination, headers, avatars, tab order, and notification UI

- Fix cursor pagination: use string comparison (not Date objects) for
  published field queries in both timeline and notifications
- Fix "Older" cursor to use oldest item's date, not newest
- Remove redundant parent breadcrumb from all AP page headings
- Reorder tabs: Notes first, All last
- Fix avatar loading: non-destructive hide/show with lazy loading
- Add actor avatars with type badge overlay to notification cards
- Add Fediverse navigation group in sidebar

views/activitypub-profile.njk

@@ -10,7 +10,7 @@
 {% from "prose/macro.njk" import prose with context %}
 
 {% block content %}
-  {{ heading({ text: title, level: 1, parent: { text: __("activitypub.title"), href: mountPath } }) }}
+  {{ heading({ text: title, level: 1 }) }}
 
   {% if result %}
     {{ notificationBanner({ type: result.type, text: result.text }) }}