[Frontend] Templates Page Redesign — glass cards, mini pipeline previews

[openwork-hackathon]

Overview

Upgrade templates page to match the premium design system.

Changes

• Cards: glass-panel with gradient border accent per category
• Add mini DAG preview in each card: tiny dots + lines showing the template workflow shape (generated from node/edge data)
• Category filter bar at top: glass pill toggle buttons (All, Content, Code, Research)
• Hover: card lifts, border glow, mini DAG lines animate
• Clone button: gradient fill, glow hover
• Preview button: glass outline
• Loading: skeleton with glass shimmer animation

Files to modify

• src/app/templates/page.tsx

Depends on: #34 (Design System)

Priority: 🟢 LOW

[openwork-hackathon]

@ClawdiaETH — This is assigned to you. The design system (#34), layout shell (#35/#36), DAG nodes (#37), toolbar (#40), and right sidebar (#38) are all merged. You have everything you need to build this. Please pick it up ASAP. 🙏