feat(ui): add CTA card side column to blog posts - #79

What & why

Blog posts render as a single centred article, so the only promo surface is an inline section at the bottom — which readers reach only after finishing the piece. This adds a side column beside the article for marketing CTAs.

Content model

cards.cta-card — a generic, reusable component: title, optional image, description, one link, and a primary | secondary button style.

It is deliberately named for its structure, not a use case. An editor can make it a demo promo, a sales prompt, a webinar invite or a docs link with no schema change, and it can be dropped into any dynamic zone — not just the blog.

The link reuses the existing utilities.link, so a CTA points at either an internal page relation or an external URL with newTab — the same choice the hero section already offers, with the same conditional fields (href shows for external, the page picker for page).

Two-tier placement. sidebar is a repeatable cards.cta-card on both:

The single type is the primary home because the cards are evergreen. Re-adding them to every post by hand would not survive contact with a real content team, and new posts would otherwise publish with an empty column. A post that sets its own column replaces the default outright rather than merging — merge order would be ambiguous and invisible to the editor.

Layout

• Article and column are centred as one group inside the standard page container, so the column's right edge lands on the same grid as the hero and navbar.
• The share rail is now anchored to the article (left-full) instead of a viewport offset (left-[calc(50%+27rem+1rem)]) that only cleared above 1536px.
• The column shows from xl and sticks on scroll, like the share rail.
• Below xl the cards flow into the article width rather than vanishing or keeping the rail's narrow column.

Tradeoff: with a column present the article narrows from 864px to 616px — that is what lets four tracks fit the page grid. Posts without a sidebar are completely unchanged.

Testing

Verified locally against Strapi + Next: both link modes resolve correctly (type: page → the page's fullPath, type: external → the URL with target="_blank" rel="noopener noreferrer"), cards render beside the article and not below it, the image sits between heading and button, the column sticks through a long scroll, cards fall inline below xl, and there is no horizontal overflow at any breakpoint.

tsc --noEmit and ESLint are clean on all changed files.

Note for reviewers

apps/strapi/types/generated/* was hand-written in typegen's format because pnpm generate:types currently fails on main with e.charAt is not a function — it fails on a clean checkout too, so it predates this branch. Those files should be regenerated once that is fixed.

🤖 Generated with Claude Code