engine: interaction.tie, tie.edit and tie.delete

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

crates/engine/src/schema.rs

@@ -107,6 +107,7 @@ pub enum Collection {
     ReferencePoint,
     Coupling,
     Contact,
+    Tie,
     Mass,
     Spring,
     BoundaryCondition,
@@ -128,6 +129,7 @@ impl Collection {
             Collection::ReferencePoint => "reference point",
             Collection::Coupling => "coupling",
             Collection::Contact => "contact",
+            Collection::Tie => "tie",
             Collection::Mass => "point mass",
             Collection::Spring => "spring",
             Collection::BoundaryCondition => "boundary condition",
@@ -151,6 +153,7 @@ impl Session {
             Collection::ReferencePoint => Box::new(m.reference_points().keys().map(String::as_str)),
             Collection::Coupling => Box::new(m.couplings().keys().map(String::as_str)),
             Collection::Contact => Box::new(m.contacts().keys().map(String::as_str)),
+            Collection::Tie => Box::new(m.ties().keys().map(String::as_str)),
             Collection::Mass => Box::new(m.masses().keys().map(String::as_str)),
             Collection::Spring => Box::new(m.springs().keys().map(String::as_str)),
             Collection::BoundaryCondition => Box::new(m.boundary_conditions().keys().map(String::as_str)),