Bricks Builder MCP v1.12.0

Add accessibility, performance, and schema tools

Bump plugin to v1.12.0 and register three new tools in the Tools_Registry: Tool_Performance, Tool_Accessibility and Tool_Schema. Added new MCP endpoints and capability mappings for structured data (get/update/delete), accessibility audit, SEO audit/heading structure, performance audit, and breakpoints writes. Implemented Tool_Accessibility (WCAG-style checks for images, headings, ARIA, semantic HTML, links), Tool_Performance (Core Web Vitals focused checks: images, element counts/nesting, CSS bloat, font preload hints, and performance tips) and Tool_Schema (read/update/delete stored JSON-LD per post, output JSON-LD in wp_head, and peek Yoast/RankMath). Updated registry to include the new tools and corresponding read/write cache targets.