Support all block-editor post types, not just posts

[pento]

Problem

The MCP server currently only supports post_type = 'post'. The WordPress REST API endpoint GET /wp/v2/posts/{id} returns a 404 for pages and custom post types — each post type has its own controller and endpoint (e.g., /wp/v2/pages/ for pages).

This means wp_open_post fails for pages, WooCommerce products, or any custom post type that uses the block editor.

Affected areas

MCP server (src/wordpress/api-client.ts)

• getPost(), updatePost(), listPosts() all hardcode /wp/v2/posts
• Need to resolve the correct REST base for a given post type (e.g., /wp/v2/pages for page)

WordPress plugin

• getEntityRecord('postType', 'post', id) in ConnectionStatus hardcodes the post type when looking up titles for "Editing: ..." display
• Command post_id doesn't include the post type, so the plugin can't resolve the correct entity

MCP tools

• wp_open_post / wp_list_posts / wp_create_post should accept a post type parameter (defaulting to post)
• wp_read_post output should indicate the post type

Sync protocol

• The Yjs room format is already post-type-aware: postType/{type}:{id} — this should work as-is

Approach

1. During connect(), fetch available post types from GET /wp/v2/types to build a map of post_type → rest_base
2. Add an optional postType parameter to wp_open_post, wp_list_posts, wp_create_post (default: post)
3. Use the resolved rest_base for all REST API calls on the opened post
4. Include post_type in the command REST response so the plugin can resolve entity records correctly