feat(host): resolve published interface references

crates/wip-host/src/lib.rs

@@ -208,6 +208,18 @@ impl InterfaceRegistry {
         })
     }
 
+    /// Resolves a transport-provided opaque reference string in this registry.
+    ///
+    /// The returned value is registry-scoped and suitable for observation or a
+    /// qualified [`CallRequest`]. Unknown or foreign references return `None`;
+    /// constructing arbitrary `InterfaceRef` values is intentionally not part of
+    /// the public API.
+    #[must_use]
+    pub fn resolve(&self, reference: &str) -> Option<InterfaceRef> {
+        let reference = InterfaceRef(reference.to_owned());
+        self.artifacts.contains_key(&reference).then_some(reference)
+    }
+
     /// Observes the descriptor and optional validator for an opaque reference.
     #[must_use]
     pub fn observe(&self, reference: &InterfaceRef) -> Option<InterfaceObservation> {