feat(admin): Add global admin search for blog entries without ElasticSearch (#43)

[logmedia-openclaw]

Summary

Adds the ability to search blog entries in Shopware's global admin backend search - without requiring ElasticSearch.

Changes

Backend (PHP)

• BlogEntryAdminSearchHandler.php - DAL-based search handler using SearchTermInterpreter and MultiFieldScoreFilter
• BlogAdminSearchController.php - REST endpoint at POST /api/_admin/blog-search
• Updated services.xml to register new services

Frontend (JavaScript)

• blog-search-api.service.js - API service for blog search
• blog-search.mixin.js - Mixin for integration with search bar
• Updated main.js to register blog search service and types
• Added snippets (de-DE, en-GB) for search labels

How it works

Since Shopware's native admin search (/api/_admin/es-search) is entirely dependent on ElasticSearch with no DAL fallback, this implementation provides:

1. A custom REST endpoint that accepts search terms
2. Uses DAL with SearchTermInterpreter to parse the query
3. Applies MultiFieldScoreFilter for relevance scoring across title, slug, and teaser fields

Usage

The blog search can be integrated into the admin UI by decorating the sw-search-bar component to use the blog search service. The endpoint can also be called directly:

POST /api/_admin/blog-search
{
"term": "search term",
"limit": 10
}

Notes

• Works without ElasticSearch installed (explicit requirement from Can we make the blog entries in the administration searchable? #43)
• Compatible with Shopware 6.7+
• Uses existing SearchRanking flags on BlogEntryDefinition fields

Closes #43