engine: friction output of implicit contact

solve.nonlinear counts the slipping nodes, solve.probe gives a secondary node's shear traction
and slip, and the results display draws contact_shear and contact_slip, contact_status coding
stick and slip.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo

crates/engine/src/catalogue.rs

@@ -428,7 +428,7 @@ pub static CATALOGUE: &[Capability] = &[
         "Contact Pair",
         Interactions,
         "Contact",
-        "Contact between two surfaces: with friction in explicit dynamics, frictionless mortar contact in nonlinear static steps",
+        "Contact between two surfaces: with friction in explicit dynamics, mortar contact with friction in nonlinear static steps",
         &["interaction.contact.edit", "interaction.contact.delete"],
     ),
     ready(