Add action buttons (Like, Boost) to the reactions block

[pfefferle]

Preparation for #2792

Proposed changes:

• Add optional Like and Boost action buttons inline in each reaction group of the Fediverse Reactions block.
• Clicking a button opens a full-size modal dialog where visitors can copy the post URL or enter their Fediverse handle to interact from their home server (FEP-3b86, OStatus, and Mastodon fallback).
• Add posts/{id}/remote-intent REST endpoint returning { url, template } — consistent with the existing remote-follow and remote-reply endpoints.
• Refactor Webfinger::get_remote_follow_endpoint() to delegate to new get_intent_endpoint() method with FEP-3b86 support.
• Pass $intent to Interaction Controller filters for extensibility.
• Reuse the shared modal infrastructure (Blocks::render_modal() + createModalStore()) — the modal dynamically switches between compact (reactors list) and full-size (intent dialog) modes.
• Feature is opt-in via a showActions block attribute with editor toggle in Inspector Controls.
• Share saved Fediverse profile across blocks via localStorage (fediverse-remote-user key).

Other information:

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

Testing instructions:

• Go to a post that has existing Fediverse reactions (likes, reposts).
• Edit the post and select the Reactions block. In the sidebar, enable "Show action buttons".
• Save and view the post on the frontend.
• Verify Like/Boost buttons appear inline at the start of each reaction group row.
• Click a button — a full-size modal should open with two sections: "Post URL" (with copy button) and "Your Profile" (with input field).
• Enter a valid Fediverse handle (e.g. @user@mastodon.social) and click "Go" — the remote server's interaction page should open in a new tab.
• Check the "Remember my profile" checkbox, submit, then open a different action button — the profile should be pre-filled.
• Toggle off "Show action buttons" in the editor — buttons should disappear.
• Verify the compact reactors list modal (clicking the count label) still works as before.

Changelog entry

• Automatically create a changelog entry from the details below.

Changelog Entry Details

Significance

• Minor

Type

• Added - for new features

Message

Add optional Like and Boost action buttons to the Fediverse Reactions block, allowing visitors to interact with posts from their own server.

[Copilot]

Pull request overview

Adds opt-in Like/Boost “remote intent” actions to the Fediverse Reactions block, backed by a new REST endpoint and WebFinger intent discovery (FEP-3b86 with fallbacks).

Changes:

• Adds posts/{id}/remote-intent REST endpoint and extends WebFinger with get_intent_endpoint() (FEP-3b86 + OStatus + Mastodon fallback).
• Updates the Reactions block (editor + frontend Interactivity store) to show action buttons and a full-size intent modal with localStorage profile persistence.
• Extends shared modal rendering to support dynamic titles and compact/full-size switching.

Reviewed changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
tests/phpunit/tests/includes/rest/class-test-post-controller.php	Adds route registration + response/validation tests for the new remote-intent endpoint.
tests/phpunit/tests/includes/class-test-webfinger.php	Adds unit tests for Webfinger::get_intent_endpoint() across supported discovery/fallback paths.
src/reactions/view.js	Implements intent modal behavior, REST call, clipboard copy, and localStorage persistence in the Interactivity store.
src/reactions/style.scss	Styles the inline action buttons and the intent dialog inside the shared modal.
src/reactions/render.php	Adds showActions attribute handling, renders action buttons and the new dual-mode modal contents, and configures i18n/context.
src/reactions/reactions.js	Updates editor-side React preview to display (disabled) action buttons when enabled.
src/reactions/edit.js	Adds Inspector toggle for the showActions attribute and passes it through to the preview.
src/reactions/block.json	Introduces the showActions block attribute.
includes/rest/class-post-controller.php	Registers the remote-intent route and implements the { url, template } response.
includes/rest/class-interaction-controller.php	Passes $intent through interaction filters for extensibility.
includes/class-webfinger.php	Refactors remote-follow to delegate to new intent endpoint discovery with FEP-3b86 support + fallbacks.
includes/class-blocks.php	Extends shared modal renderer with title_binding + dynamic compact class binding support.
build/reactions/view.js	Built asset reflecting src/reactions/view.js changes.
build/reactions/view.asset.php	Updates built asset metadata for the view script.
build/reactions/style-index.css	Built CSS reflecting src/reactions/style.scss changes.
build/reactions/style-index-rtl.css	Built RTL CSS reflecting src/reactions/style.scss changes.
build/reactions/render.php	Built render file reflecting src/reactions/render.php changes.
build/reactions/index.js	Built editor script reflecting src/reactions/* changes.
build/reactions/index.asset.php	Updates built asset metadata for the editor script.
build/reactions/block.json	Built block metadata reflecting src/reactions/block.json changes.
.github/changelog/2988-from-description	Adds changelog entry for the feature.