Admin UI consistency framework

This project now includes a shared admin UI framework for consistent spacing, control sizing, and action layout in custom admin templates.

Goals

• Ensure buttons and action links render at a predictable, uniform height.
• Use common spacing and panel primitives so custom views feel native.
• Provide a repeatable pattern for future admin customizations.
• Steer administrators toward developed and tested UI capabilities instead of recipe-like or programmer-oriented configuration surfaces.
• Keep SIGILS available where basic templating or default values improve usability without introducing control flow.