Add type filter for feed based on ap_object_type taxonomy

This adds a button-based filter to the feed that allows users to filter posts by ActivityPub object type (Article, Note, etc.).

Changes:
- Add ap_object_type field to FeedPost interface
- Add apObjectType parameter to useFeed hook with REST API integration
- Create TypeFilter component using WordPress ButtonGroup
- Integrate TypeFilter into feed stage with localStorage persistence
- Filter buttons appear in DataViews header aligned to the right

The selected filter is persisted to localStorage so it's remembered across sessions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: pfefferle

build/social-web/feed-stage.js

@@ -1 +1 @@
-<?php return array('dependencies' => array('react', 'react-dom', 'react-jsx-runtime', 'wp-commands', 'wp-components', 'wp-compose', 'wp-core-data', 'wp-data', 'wp-data-controls', 'wp-date', 'wp-dom', 'wp-element', 'wp-html-entities', 'wp-i18n', 'wp-keyboard-shortcuts', 'wp-keycodes', 'wp-notices', 'wp-preferences', 'wp-primitives', 'wp-private-apis', 'wp-url', 'wp-warning'), 'version' => '658866a5e77c1bf57d37');
+<?php return array('dependencies' => array('react', 'react-dom', 'react-jsx-runtime', 'wp-commands', 'wp-components', 'wp-compose', 'wp-core-data', 'wp-data', 'wp-data-controls', 'wp-date', 'wp-dom', 'wp-element', 'wp-html-entities', 'wp-i18n', 'wp-keyboard-shortcuts', 'wp-keycodes', 'wp-notices', 'wp-preferences', 'wp-primitives', 'wp-private-apis', 'wp-url', 'wp-warning'), 'version' => '28980da823d4c9a1ef30');