Preserve inherited reference path origins

docs/config.md

@@ -80,10 +80,12 @@ umask, setgid inheritance, and default ACLs; see [Operations](operations.md#cach
 
 Every nonempty relative configured destination or reference path resolves from
 the canonical directory of the file that supplies its surviving declaration.
-This includes imported fragments and selected configuration overlays. Built-in
-relative destinations use the selected main configuration file's directory;
-explicit `--output-dir` and `--debug-dir` values use the invocation working
-directory. Absolute values remain unchanged.
+This includes imported fragments, selected configuration overlays, and values
+copied through inheritance: the copied value keeps its original declaring
+file. A child-supplied replacement resolves from the child's declaring file.
+Built-in relative destinations use the selected main configuration file's
+directory; explicit `--output-dir` and `--debug-dir` values use the invocation
+working directory. Absolute values remain unchanged.
 
 The root file can use ConfigKit imports to compose disjoint definitions. Imports
 and selected overlays remain under the configuration root; they do not merge or

docs/internal/configuration.md

@@ -28,10 +28,13 @@ at their respective [CLI](cli.md), [pipeline](pipeline.md), and
 
 ## Loading And Validation
 
-ConfigKit acquires the selected root, imports, optional selected overlay, and
-explicit CLI overrides in precedence order. Its document definition supplies
-typed defaults, source-aware path normalization, and structural validation
-before conversion to the independently owned runtime **Config**. Only
+ConfigKit composes the selected root, imports, optional selected overlay, and
+explicit CLI overrides in precedence order, then expands native sibling
+inheritance before typed decoding. The document definition supplies typed
+defaults and structural validation; Notarius's recorded resolution changes
+normalize configured paths after decode. Path normalization follows the source
+of the surviving value, including a value copied through inheritance, rather
+than the inheritance directive's location. Only
 `NOTARIUS_CONFIG` participates in discovery; retired field-level environment
 variables do not participate in loading. Version 5 decoding rejects scalar
 module bindings and scalar external references. ConfigKit retains redacted,

docs/roadmap/implementation.md

@@ -227,6 +227,8 @@ not change defaults or add CLI flags for arbitrary configuration overrides.
 
 ## Stage 4 — Verify Declaration-Relative Paths Through Inheritance
 
+> Completion: complete.
+
 Goal: keep inherited resource paths anchored to the original declaration.
 
 Inspect `document_paths.go`, `document_paths_test.go`, the original-path map in

internal/core/config/inheritance_test.go

@@ -331,3 +331,105 @@ pipelines:
 		t.Fatalf("override-inherited repair budget = %d, want 3", got)
 	}
 }
+
+func TestInheritedReferencePathsKeepDeclaringSource(t *testing.T) {
+	t.Parallel()
+
+	root := t.TempDir()
+	parentDirectory := filepath.Join(root, "parents")
+	childDirectory := filepath.Join(root, "children")
+	overlayDirectory := filepath.Join(root, "overlays")
+	fixtureDirectory := filepath.Join(root, "fixtures")
+	for _, directory := range []string{parentDirectory, childDirectory, overlayDirectory, fixtureDirectory} {
+		if err := os.MkdirAll(directory, 0o700); err != nil {
+			t.Fatal(err)
+		}
+	}
+	for _, name := range []string{"shared.txt", "parent.txt", "child.txt", "step.txt", "overlay.txt"} {
+		if err := os.WriteFile(filepath.Join(fixtureDirectory, name), []byte("fixture\n"), 0o600); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	parent := filepath.Join(parentDirectory, "pipelines.yml")
+	if err := os.WriteFile(parent, []byte(`pipelines:
+  " parent ":
+    input: {module: input}
+    references:
+      " shared ": {path: ../fixtures/shared.txt}
+      nested:
+        extends: " shared "
+      source: {path: ../fixtures/parent.txt}
+    steps:
+      - id: first
+        references:
+          step-source: {path: ../fixtures/step.txt}
+        artifacts:
+          summary:
+            extract: {module: extract}
+`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	child := filepath.Join(childDirectory, "pipelines.yml")
+	if err := os.WriteFile(child, []byte(`pipelines:
+  child:
+    extends: " parent "
+    references:
+      source: {path: ../fixtures/child.txt}
+`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	main := filepath.Join(root, "notarius.yml")
+	if err := os.WriteFile(main, []byte(`version: 5
+configkit:
+  imports:
+    - path: parents/pipelines.yml
+    - path: children/pipelines.yml
+`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(overlayDirectory, "development.yml"), []byte(`pipelines:
+  " parent ":
+    references:
+      " shared ": {path: ../fixtures/overlay.txt}
+`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+
+	loaded, err := loadConfig(main, LoadOptions{})
+	if err != nil {
+		t.Fatalf("loadConfig() error = %v", err)
+	}
+	assertReferencePath := func(pipelineID, referenceID, want string) {
+		t.Helper()
+		if got := loaded.Config.Pipelines[pipelineID].References[referenceID].Path; got != want {
+			t.Errorf("%s reference %s path = %q, want %q", pipelineID, referenceID, got, want)
+		}
+	}
+	assertReferencePath("parent", "shared", filepath.Join(fixtureDirectory, "shared.txt"))
+	assertReferencePath("child", "shared", filepath.Join(fixtureDirectory, "shared.txt"))
+	assertReferencePath("child", "nested", filepath.Join(fixtureDirectory, "shared.txt"))
+	assertReferencePath("parent", "source", filepath.Join(fixtureDirectory, "parent.txt"))
+	assertReferencePath("child", "source", filepath.Join(fixtureDirectory, "child.txt"))
+	if got := loaded.Config.Pipelines["child"].Steps[0].References["step-source"].Path; got != filepath.Join(fixtureDirectory, "step.txt") {
+		t.Errorf("inherited step reference path = %q", got)
+	}
+
+	overlaid, err := loadConfig(main, LoadOptions{Overlay: "development"})
+	if err != nil {
+		t.Fatalf("loadConfig() with overlay error = %v", err)
+	}
+	for _, pipelineID := range []string{"parent", "child"} {
+		for _, referenceID := range []string{"shared", "nested"} {
+			if got, want := overlaid.Config.Pipelines[pipelineID].References[referenceID].Path, filepath.Join(fixtureDirectory, "overlay.txt"); got != want {
+				t.Errorf("overlaid %s reference %s path = %q, want %q", pipelineID, referenceID, got, want)
+			}
+		}
+	}
+	if got, want := overlaid.Config.Pipelines["child"].References["source"].Path, filepath.Join(fixtureDirectory, "child.txt"); got != want {
+		t.Errorf("child replacement path = %q, want %q", got, want)
+	}
+	if got, want := overlaid.Config.Pipelines["child"].Steps[0].References["step-source"].Path, filepath.Join(fixtureDirectory, "step.txt"); got != want {
+		t.Errorf("overlaid inherited step reference path = %q, want %q", got, want)
+	}
+}