Add latest blog posts PrettyBlocks slider

[CySSoO]

Motivation

• Provide a PrettyBlocks block that displays the latest blog posts following the provided mockup.
• Let the admin enable a Bootstrap slider and control items per slide on mobile and desktop as well as the total number of posts.
• Reuse existing formatting helpers so posts appear with thumbnails, excerpts and category links.
• Offer a CTA linking to the full blog.

Description

• Register a new PrettyBlocks block in hookActionRegisterBlock with config fields bootstrap_slider, items_per_slide_mobile, items_per_slide_desktop and total_posts.
• Add hookBeforeRenderingEverpsblogLatestPosts which fetches posts via EverPsBlogPost::getLatestPosts, formats them with formatPrettyBlocksPost and exposes blog_url.
• Add the rendering template views/templates/block/latest-posts.tpl implementing responsive Bootstrap carousels (mobile/desktop) and a non-slider grid fallback.
• Add safe defaults and minimums for items_per_slide_* and total_posts (default 6) to avoid invalid values.

Testing

• No automated tests were executed for this change.

---

Codex Task