RI-510 Review v2 admin layout

[pixl8-jg]

This MR is a review/polish pass on the v2 admin layout.

• Icons: adds ~20 missing Lucide/brand SVGs and expands the FontAwesome→SVG map (incl. fa-dashboard). The icon service now resolves colour-suffixed classes (e.g. fa-trash red) to their base icon instead of rendering blank.
• Card component: fixes the header layout/logic so icon, title and description render/order correctly.
• Progress bar: consolidates skin definitions and adds warning and danger skins.
• Onboarding checklist: moves styles into the v2 theme (converted to LESS variables), fixes the CSS include path, and adds the s-main header gradient.