fix(repo): drop stale TAX_FAMILY references (v0.2.1 P1 hotfix)

v0.2.0 removed TAX_FAMILY from PR_Core_Peptide_CPT but left two stale
references in PR_Core_Peptide_Repository:
  - find_all() family filter branch (class-pr-core-peptide-repository.php:95-102)
  - post_to_dto() families taxonomy lookup (class-pr-core-peptide-repository.php:138)

JSON-LD emission on single-peptide templates called find_by_id() ->
post_to_dto() which hit the undefined constant and killed every peptide
detail page render mid-wp_head().

Fix:
  - family filter is silently ignored until a future minor bump
    removes it from the REST schema.
  - post_to_dto() hardcodes $families = [] so the DTO still carries
    the field (REST response shape unchanged for existing clients).

Out-of-scope follow-ups:
  - Post-mortem on why the v0.2.0 QA gate missed this (unit tests
    exercised the CPT class in isolation, not the repository's
    consumption of its constants).
  - Add an integration-style test for JSON-LD emission on a single
    peptide so any future CPT-class refactor catches repository drift.

peptide-repo-core.php

@@ -3,7 +3,7 @@
  * Plugin Name: Peptide Repo Core
  * Plugin URI:  https://peptiderepo.com
  * Description: Canonical peptide schema — shared data layer for the peptiderepo.com ecosystem. Provides the peptide CPT, dosing rows, legal status cells, AI candidate queue, disclaimer component, and JSON-LD output.
- * Version:     0.2.0
+ * Version:     0.2.1
  * Author:      peptiderepo
  * Author URI:  https://peptiderepo.com
  * License:     GPL-2.0-or-later
@@ -22,7 +22,7 @@ if ( ! defined( 'ABSPATH' ) ) {
 
 /* ── Constants ────────────────────────────────────────────────────────── */
 
-define( 'PR_CORE_VERSION', '0.2.0' );
+define( 'PR_CORE_VERSION', '0.2.1' );
 define( 'PR_CORE_PLUGIN_FILE', __FILE__ );
 define( 'PR_CORE_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );
 define( 'PR_CORE_PLUGIN_URL', plugin_dir_url( __FILE__ ) );