[TheSilentPro]

Summary

Implements #98 without changing the existing Alphabet category behavior.

Alphabet still opens the normal full result list. A new configurable Browse by Style button appears in slot 4 on the unfiltered Alphabet category results. It opens a dedicated style browser backed by existing font-* tags in the remote catalog.

Behavior

• keeps the normal 293-page Alphabet browse flow available;
• adds an optional style browser at search.category-style-browser (default slot 4);
• discovers styles dynamically from registered font-* tags rather than hardcoding the current list;
• uses representative heads as style icons and strips HeadDB item IDs from those GUI-only icons;
• filters style results using the existing category + tag query path;
• preserves navigation: Alphabet results → styles → style results → styles → Alphabet results;
• shows contextual titles such as Alphabet · Oak for style results;
• auto-merges the new GUI icon, title and slot defaults into existing gui.yml files.

The implementation is Paper-only and does not change the HeadDB API, catalog schema, pipeline format, permissions, or head records.