Preserve closed callback failures through the facade

lifecycle.go

@@ -134,7 +134,9 @@ func (r *Result[T]) Diagnostics() []Diagnostic {
 }
 
 // IsExplicit reports whether surviving input explicitly defined path.
-func (r *Resolution) IsExplicit(path Path) bool { return r.value.IsExplicit(toEnginePath(path)) }
+func (r *Resolution) IsExplicit(path Path) bool {
+	return r.engineContext().IsExplicit(toEnginePath(path))
+}
 
 // InputInfo returns detached entry-state metadata for path. The entry state is
 // the decoded configuration, including retained static defaults, immediately
@@ -144,7 +146,7 @@ func (r *Resolution) IsExplicit(path Path) bool { return r.value.IsExplicit(toEn
 // InputInfo is valid only during the resolution callback. See the configuration
 // contract for source and provenance semantics.
 func (r *Resolution) InputInfo(path Path) (FieldInfo, bool) {
-	value, ok := r.value.InputInfo(toEnginePath(path))
+	value, ok := r.engineContext().InputInfo(toEnginePath(path))
 	return fromEngineFieldInfo(value), ok
 }
 
@@ -155,47 +157,62 @@ func (r *Resolution) InputInfo(path Path) (FieldInfo, bool) {
 // Source is valid only during the resolution callback. See the configuration
 // contract for source and provenance semantics.
 func (r *Resolution) Source(id string) (SourceInfo, bool) {
-	value, ok := r.value.Source(id)
+	value, ok := r.engineContext().Source(id)
 	return fromEngineSourceInfo(value), ok
 }
 
 // Record declares the intent for a resolver mutation. A container path covers
 // mutations to its descendants.
 func (r *Resolution) Record(path Path, kind ChangeKind, reason string, dependencies ...Path) {
-	r.value.Record(toEnginePath(path), engine.ChangeKind(kind), reason, toEnginePaths(dependencies)...)
+	r.engineContext().Record(toEnginePath(path), engine.ChangeKind(kind), reason, toEnginePaths(dependencies)...)
 }
 
 // Error reports a safe, value-free resolution error at path.
 func (r *Resolution) Error(path Path, message string, related ...Path) {
-	r.value.Error(toEnginePath(path), message, toEnginePaths(related)...)
+	r.engineContext().Error(toEnginePath(path), message, toEnginePaths(related)...)
 }
 
 // Warning reports a safe, value-free resolution warning at path.
 func (r *Resolution) Warning(path Path, message string, related ...Path) {
-	r.value.Warning(toEnginePath(path), message, toEnginePaths(related)...)
+	r.engineContext().Warning(toEnginePath(path), message, toEnginePaths(related)...)
 }
 
 // Default assigns and records value only when path was absent from surviving
 // input. Static defaults are not considered explicit.
 func Default[V any](resolution *Resolution, path Path, target *V, value V, reason string, dependencies ...Path) {
-	engine.Default(resolution.value, toEnginePath(path), target, value, reason, toEnginePaths(dependencies)...)
+	engine.Default(resolution.engineContext(), toEnginePath(path), target, value, reason, toEnginePaths(dependencies)...)
 }
 
 // Normalize assigns and records value regardless of input presence.
 func Normalize[V any](resolution *Resolution, path Path, target *V, value V, reason string, dependencies ...Path) {
-	engine.Normalize(resolution.value, toEnginePath(path), target, value, reason, toEnginePaths(dependencies)...)
+	engine.Normalize(resolution.engineContext(), toEnginePath(path), target, value, reason, toEnginePaths(dependencies)...)
 }
 
 // Error reports a value-free application error at path. Related paths are
 // resolved to source locations when possible.
 func (v *Validation) Error(path Path, message string, related ...Path) {
-	v.value.Error(toEnginePath(path), message, toEnginePaths(related)...)
+	v.engineContext().Error(toEnginePath(path), message, toEnginePaths(related)...)
 }
 
 // Warning reports a value-free application warning at path. Related paths are
 // resolved to source locations when possible.
 func (v *Validation) Warning(path Path, message string, related ...Path) {
-	v.value.Warning(toEnginePath(path), message, toEnginePaths(related)...)
+	v.engineContext().Warning(toEnginePath(path), message, toEnginePaths(related)...)
+}
+
+// Pass nil through so the engine remains the owner of the callback guard.
+func (r *Resolution) engineContext() *engine.Resolution {
+	if r == nil {
+		return nil
+	}
+	return r.value
+}
+
+func (v *Validation) engineContext() *engine.Validation {
+	if v == nil {
+		return nil
+	}
+	return v.value
 }
 
 func toEngineOptions[T any](options Options[T]) engine.Options[T] {