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/class-pr-core.php

@@ -35,6 +35,14 @@ class PR_Core {
 		$topic_tax = new PR_Core_Topic_Taxonomy();
 		$topic_tax->register_hooks();
 
+		// Register repo_daily CPT (fires on init).
+		$repo_daily_cpt = new PR_Core_Repo_Daily_CPT();
+		$repo_daily_cpt->register_hooks();
+
+		// Register repo_daily_category taxonomy (fires on init).
+		$repo_daily_tax = new PR_Core_Repo_Daily_Taxonomy();
+		$repo_daily_tax->register_hooks();
+
 		// One-shot rewrite flush on in-place version bumps. Runs at the very
 		// end of init (priority 999) so all CPTs/taxonomies — ours and
 		// anyone else's — are registered first. Handles updates deployed