- Register convert_friend_users_to_subscriptions batched migration
- Simplify role setup to subscription-only; remove friend/acquaintance
- Remove multi-cap checks replaced by single has_cap('subscription')
- Remove make_friend(), convert_to_user(), dead convert_to_user call
- Remove WP_User_Query role lookups from all_subscriptions/search/starred

- Simplify multi-cap guards to single has_cap('subscription') check
- Remove convert-to-user/convert-from-user GET handlers and UI links
- Remove get_friend_roles() method (checked for cap that no longer exists)
- Remove friends_default_friend_role option (no longer read anywhere)
- Remove role_friend/role_acquaintance JS vars
- Replace role__in WP_User_Query with User_Query::all_subscriptions()
- Simplify edit-friend.php Type row to always show Virtual User
- Simplify friends-list.php unfriend action (always Unfriend, not Delete)
- Remove followed_by assignment based on friend cap (always false)

The friend role was removed in this branch; update the test setup
to use the subscription role so tests pass.

- Replace "as a friend" with "subscribe to" for the first-subscription CTA
- Simplify "extend your network" to mention only subscriptions and Fediverse
- When ActivityPub is not installed, mention Fediverse following as a possibility
- Remove the automatic status bullet point (feature removed)
- Show ActivityPub and EMA plugins as installed with settings link when active

…nd optimize with bulk SQL

The migration was only targeting friend/acquaintance roles but sites may already
have users with the subscription role. Also replaces the slow per-post
wp_update_post loop with bulk INSERT/UPDATE queries for dramatically faster
conversion of users with many posts.

Use array_fill with implode to build placeholders inline instead of
interpolating a variable, satisfying both wpdb->prepare() placeholder
counting and PHPCS rules.

The direct $wpdb UPDATE doesn't invalidate WordPress post object caches,
so subsequent get_post() calls return stale post_author values. Query
affected post IDs first and clean their caches after the update.