Rework Follower Structure

[pfefferle]

Rework follower structure to enable reuse of the pattern for the following mechanism.

This is the first major change to the follower structure, enabling the unified storage of "Remote Actors" — such as followers, followings, and mentioned actors. The first step is to migrate all generic functionality to the Actors collection and use the Followers collection solely to map an actor to a local user.

The next steps will be (further PRs):

• Deprecate the Follower model in favor of the generic Actor model
• Establish class structure for Followings
• Add an internal API for managing Followings

Proposed changes:

• Move Actor handling to the Actors collection to enable a unified structure for followers and followings
• Avoid transforming post-type objects into Actor objects for internal operations to reduce resource usage and simplify handling
• Update tests

Other information:

• Have you written new tests for your changes, if applicable?

Testing instructions:

• No user facing changes
• See tests

Changelog entry

• Automatically create a changelog entry from the details below.

Changelog Entry Details

Significance

• Patch
• Minor
• Major

Type

• Added - for new features
• Changed - for changes in existing functionality
• Deprecated - for soon-to-be removed features
• Removed - for now removed features
• Fixed - for any bug fixes
• Security - in case of vulnerabilities

Message

Reworked follower structure to simplify handling and enable reuse for following mechanism.

[obenland]

There are a few undefined method and properties calls that would benefit from another iteration before this gets merged

[Copilot]

Pull Request Overview

This PR overhauls the follower subsystem by consolidating all remote-actor storage and operations into a single Actors custom post type.
Key changes:

• Redirect all follower CRUD and error-tracking APIs to the new Actors collection and deprecate the standalone Follower model.
• Update Follow, Update, Move, Delete handlers to upsert and query via Actors methods instead of Follower.
• Adjust scheduler hooks and all tests to work with Actors (WP_Post) rather than the old Follower model.

Reviewed Changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
includes/model/class-follower.php	Refactored delete and error methods to delegate to Actors.
includes/collection/class-followers.php	Updated metadata APIs; remove_follower now uses post meta.
includes/handler/class-follow.php	Use WP_Post ($remote_actor) instead of Follower; changed queue_accept actor.
includes/handler/class-move.php	Handle Move via Actors CPT (get_remote_by_uri, upsert).
includes/class-scheduler.php	Renamed cron hooks for remote actor updates and cleanup.

Comments suppressed due to low confidence (1)

includes/handler/class-follow.php:114

• In queue_accept, setting the activity actor to the follower's guid is incorrect. The Accept must be sent by the local user, so you should use Actors::get_by_id($user_id)->get_id() instead.

		$activity->set_actor( $remote_actor->guid );

[obenland]

Let's merge and iterate if needed. Nice work!

[obenland]

I worry that moving it here will make it harder to refactor and remove.