feat: unify object observation API

crates/wip-host/tests/host.rs

@@ -467,7 +467,7 @@ fn registry_returns_atomic_canonical_observation_without_rewriting_descriptor()
 #[test]
 fn canonical_object_projection_supports_optional_metadata_and_ordered_sets() {
     let (_, provider, _) = registry_and_provider();
-    let object = provider.fetch("/document").unwrap();
+    let object = provider.observe_object("/document").unwrap();
 
     assert_eq!(object.name, "document");
     assert_eq!(object.description.as_deref(), Some("public document"));
@@ -483,7 +483,7 @@ fn canonical_object_projection_supports_optional_metadata_and_ordered_sets() {
     assert!(!format!("{object:?}").contains("secret-handle"));
     assert!(!format!("{object:?}").contains("/document"));
 
-    let empty = provider.fetch("/empty").unwrap();
+    let empty = provider.observe_object("/empty").unwrap();
     assert!(empty.interfaces.is_empty());
     assert_eq!(empty.r#ref, None);
     assert_eq!(empty.validator, None);
@@ -518,13 +518,13 @@ fn duplicate_exposure_is_rejected_and_private_state_is_not_projected() {
 fn paths_are_resolution_context_not_object_identity() {
     let (_, provider, _) = registry_and_provider();
 
-    let left = provider.fetch("/left/document").unwrap();
-    let right = provider.fetch("/right/document").unwrap();
+    let left = provider.observe_object("/left/document").unwrap();
+    let right = provider.observe_object("/right/document").unwrap();
     assert_eq!(left, right);
     assert_eq!(left.r#ref.as_deref(), Some("shared-ref"));
 
-    let first = provider.fetch("/switch").unwrap();
-    let second = provider.fetch("/switch").unwrap();
+    let first = provider.observe_object("/switch").unwrap();
+    let second = provider.observe_object("/switch").unwrap();
     assert_ne!(first.r#ref, second.r#ref);
     assert_ne!(first.validator, second.validator);
 }
@@ -603,7 +603,7 @@ fn call_failures_follow_canonical_precedence_without_execution() {
     }
     assert_eq!(provider.resolutions.get(), resolutions);
     assert_failure(
-        provider.fetch("/invalid/").unwrap_err(),
+        provider.observe_object("/invalid/").unwrap_err(),
         CallErrorKind::InvalidRequest,
         ProtocolErrorCode::InvalidRequest,
     );
@@ -849,7 +849,7 @@ fn invalid_host_responses_and_uncertain_operation_failures_use_canonical_codes()
     let (_, provider, _) = registry_and_provider();
 
     assert_failure(
-        provider.fetch("/invalid-object").unwrap_err(),
+        provider.observe_object("/invalid-object").unwrap_err(),
         CallErrorKind::Internal,
         ProtocolErrorCode::Internal,
     );