PR Core v0.5.0: Add Repo Daily CPT, taxonomy, and metaboxes

- Register repo_daily CPT at /daily/[slug]/ for editorial publications
- Register repo_daily_category taxonomy with 4 seeded terms
- Add Repo Daily metabox for author byline and clinical review flag
- Bulk-migrate _repo_daily_author on autoblogged posts (psa_source)
- Update ARCHITECTURE.md with content-type table and scanner scope
- Update CONVENTIONS.md with repo_daily meta field extension pattern
- Bump version to 0.5.0, add CHANGELOG entry

Closes v0.5.0 scope.

includes/cpt/class-pr-core-repo-daily-cpt.php

@@ -0,0 +1,80 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * Registers the repo_daily custom post type for editorial publications.
+ *
+ * What: Defines the `repo_daily` CPT for articles, guides, comparisons, and news
+ *       generated by PRAutoBlogger and published under the Boo Sheeran byline.
+ * Who calls it: PR_Core::init() on plugins_loaded.
+ * Dependencies: None.
+ *
+ * Posts register at /daily/[slug]/ with title, editor, excerpt, thumbnail,
+ * and custom-fields support. REST-enabled for programmatic access by
+ * PRAutoBlogger and other integrations.
+ *
+ * @see ARCHITECTURE.md — Repo Daily type specification.
+ * @see CONVENTIONS.md — CPT ownership and extension patterns.
+ */
+class PR_Core_Repo_Daily_CPT {
+
+	/** @var string Post type slug (repo_daily). */
+	public const POST_TYPE = 'repo_daily';
+
+	/**
+	 * Register WordPress hooks for CPT registration.
+	 *
+	 * @return void
+	 */
+	public function register_hooks(): void {
+		add_action( 'init', [ __CLASS__, 'register_post_type' ] );
+	}
+
+	/**
+	 * Register the `repo_daily` custom post type.
+	 *
+	 * Side effects: registers CPT with WordPress.
+	 *
+	 * @return void
+	 */
+	public static function register_post_type(): void {
+		if ( post_type_exists( self::POST_TYPE ) ) {
+			return;
+		}
+
+		$labels = [
+			'name'               => __( 'Repo Daily', 'peptide-repo-core' ),
+			'singular_name'      => __( 'Repo Daily', 'peptide-repo-core' ),
+			'add_new_item'       => __( 'Add New Article', 'peptide-repo-core' ),
+			'edit_item'          => __( 'Edit Article', 'peptide-repo-core' ),
+			'new_item'           => __( 'New Article', 'peptide-repo-core' ),
+			'view_item'          => __( 'View Article', 'peptide-repo-core' ),
+			'search_items'       => __( 'Search Articles', 'peptide-repo-core' ),
+			'not_found'          => __( 'No articles found', 'peptide-repo-core' ),
+			'not_found_in_trash' => __( 'No articles found in trash', 'peptide-repo-core' ),
+			'all_items'          => __( 'All Articles', 'peptide-repo-core' ),
+			'menu_name'          => __( 'Repo Daily', 'peptide-repo-core' ),
+		];
+
+		$args = [
+			'labels'             => $labels,
+			'public'             => true,
+			'publicly_queryable' => true,
+			'show_ui'            => true,
+			'show_in_menu'       => true,
+			'show_in_nav_menus'  => true,
+			'show_in_rest'       => true,
+			'rest_base'          => 'repo_daily',
+			'menu_position'      => 6,
+			'menu_icon'          => 'dashicons-edit-page',
+			'capability_type'    => 'post',
+			'map_meta_cap'       => true,
+			'hierarchical'       => false,
+			'has_archive'        => true,
+			'rewrite'            => [ 'slug' => 'daily', 'with_front' => false ],
+			'supports'           => [ 'title', 'editor', 'excerpt', 'thumbnail', 'custom-fields' ],
+		];
+
+		register_post_type( self::POST_TYPE, $args );
+	}
+}