fix: resolve architecture validation errors and warnings

- Fix JS-008: Replace raw fetch() with apiClient in letzshop-vendor-directory.js
- Fix JS-005: Add init guard to letzshop-vendor-directory.js
- Fix JS-004: Increase search region in validator (800→2000 chars) to detect
  currentPage in files with setup code before return statement
- Fix JS-001: Use centralized logger in media-picker.js
- Fix API-002: Move database query from onboarding.py to order_service.py
- Fix FE-001: Add noqa comment to search.html (shop uses custom themed pagination)
- Add audit validator to validate_all.py script
- Update frontend.yaml with vendor exclusion pattern

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/templates/shop/search.html

@@ -1,4 +1,5 @@
 {# app/templates/shop/search.html #}
+{# noqa: FE-001 - Shop uses custom pagination with vendor-themed styling (CSS variables) #}
 {% extends "shop/base.html" %}
 
 {% block title %}Search Results{% if query %} for "{{ query }}"{% endif %}{% endblock %}