fix(2327): limit horizontal layout to 3 posts

[ycanales]

Issue: #2327

Summary & Context

Fixes the layout issues by limiting the component to 3 posts when variant is horizontal.

• Figma link: https://www.figma.com/design/VhZHw3RudFNMzfPEEYchE9/UI-Kit---Foundations-Delivery?node-id=403-6216&t=OKjltnhdISNOB9Kx-4
• Link to components/page: http://localhost:8000/v3/demo/components/#post-cards-card-teal-horizontal

Changes

• At template level, limit posts to 3 when variant is horizontal.

‼️ Risks & Considerations ‼️

• This is a failsafe at component level, but the actual query in the view should efficiently query the 3 to display.

Screenshots

Before

After

Self-review Checklist

• Tag at least one team member from each team to review this PR
• Link this PR to the related GitHub Project ticket

Frontend

• UI implementation matches Figma design
• Tested in light and dark mode
• Responsive / mobile verified
• Accessibility checked (keyboard navigation, etc.)
• Ensure design tokens are used for colors, spacing, typography, etc. – No hardcoded values
• Test without JavaScript (if applicable)
• No console errors or warnings

[herzog0]

Working fine, thanks!

[kattyode]

QA Approved