Root cause: inject_graph_pieces() added plain PHP arrays to wpseo_schema_graph_pieces.
Yoast Schema_Generator::filter_graph_pieces_to_generate() calls get_class() +
is_needed() on every piece expecting Abstract_Schema_Piece objects — a plain array
produces: PHP Fatal: get_class(): Argument #1 ($object) must be of type object,
array given. All peptide monograph pages returned HTTP 500; non-peptide pages were
unaffected (is_singular guard).
Fix: remove wpseo_schema_graph_pieces hook entirely. New inject_graph_nodes() method
hooks wpseo_schema_graph at priority 12 (after enrich_webpage_piece at 11), which
receives the fully-assembled graph as array-of-arrays — safe for plain array appends.
Also adds regression test (test-jsonld-peptide-piece.php) that:
- Reproduces the v0.6.1 get_class(array) TypeError (fails-before)
- Confirms inject_graph_nodes Drug+FAQ emission is correct (passes-after)
Agent-Session: jsonld-peptide-piece-fix v0.6.2
Consolidates the `peptide` CPT under PR Core ownership, dropping the `pr_peptide` slug-collision that was 404ing all 89 peptide detail pages.
- POST_TYPE: pr_peptide -> peptide
- TAX_CATEGORY: pr_peptide_category -> peptide_category
- TAX_FAMILY + pr_peptide_family taxonomy removed
- Defensive post_type_exists/taxonomy_exists guards on both registrations
- Args harmonized as superset of PSA + prior PR Core (adds thumbnail support)
- Activation hook + init:999 version-change flush handler
- Uninstall scoped to _pr_core_authored flag (PSA-authored posts survive)
- Plugin version 0.1.1 -> 0.2.0, CHANGELOG in same commit
- ARCHITECTURE.md + CONVENTIONS.md updated with CPT ownership rule
QA gate verdict: PASS (qa-reviews/peptide-repo-core/2026-04-22-874f93b.md)
Sibling release: peptiderepo/peptide-search-ai#15 (PSA v4.5.0)
Known follow-up: manage_peptide_content capability is not granted to any role as of v0.2.0. No current UI/theme reads or writes PR Core-defined meta keys, so no regression. Follow-up thread to decide role assignment.
