diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..9745725
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,7 @@
+# Contributing
+
+## Testing ownership
+
+Integration tests prove user-visible command flows. Filesystem tests own write
+and precondition safety. Reconciliation tests own snapshot and classification
+behavior.
diff --git a/internal/reconcile/precondition_test.go b/internal/reconcile/precondition_test.go
deleted file mode 100644
index 16c7404..0000000
--- a/internal/reconcile/precondition_test.go
+++ /dev/null
@@ -1,148 +0,0 @@
-package reconcile
-
-import (
-	"os"
-	"path/filepath"
-	"testing"
-
-	"github.com/alyraffauf/cattery/internal/pathsafe"
-)
-
-func TestSnapshotPrecondition(t *testing.T) {
-	scenarios := []struct {
-		name string
-		run  func(*testing.T)
-	}{
-		{"blocking symlink ancestor", testPreconditionSymlinkAncestor},
-		{"blocking non-directory ancestor", testPreconditionFileAncestor},
-		{"missing parents tolerated", testPreconditionMissingParents},
-		{"parent race", testPreconditionParentRace},
-		{"final symlink never followed", testPreconditionFinalSymlink},
-		{"absent to present", testPreconditionAbsentTransition},
-		{"mode change", testPreconditionModeChange},
-		{"object replacement", testPreconditionIdentityReplacement},
-		{"replacement by symlink", testPreconditionSymlinkReplacement},
-	}
-	for _, scenario := range scenarios {
-		t.Run(scenario.name, scenario.run)
-	}
-}
-
-func testPreconditionSymlinkAncestor(t *testing.T) {
-	root := t.TempDir()
-	real := filepath.Join(root, "real")
-	mustTargetMkdir(t, real)
-	if err := os.Symlink(real, filepath.Join(root, "link")); err != nil {
-		t.Fatalf("make symlink: %v", err)
-	}
-	if _, err := CaptureTarget(Destination{Root: root, Relative: "link/file.txt"}); err == nil {
-		t.Fatal("precondition must reject a symlinked parent component")
-	}
-}
-
-func testPreconditionFileAncestor(t *testing.T) {
-	root := t.TempDir()
-	mustTargetFile(t, filepath.Join(root, "block"), []byte("x"))
-	if _, err := CaptureTarget(Destination{Root: root, Relative: "block/file.txt"}); err == nil {
-		t.Fatal("precondition must reject a non-directory parent component")
-	}
-}
-
-func testPreconditionMissingParents(t *testing.T) {
-	root := t.TempDir()
-	snapshot := captureAt(t, root, "missing/deep/file.txt")
-	if snapshot.Kind() != KindAbsent {
-		t.Fatalf("kind = %v, want KindAbsent", snapshot.Kind())
-	}
-	if snapshot.Parent().Path() != "" {
-		t.Fatal("missing parents must freeze as the zero parent identity")
-	}
-}
-
-func testPreconditionParentRace(t *testing.T) {
-	root := t.TempDir()
-	parent := filepath.Join(root, "dir")
-	mustTargetMkdir(t, parent)
-	mustTargetFile(t, filepath.Join(parent, "file"), []byte("x"))
-	first := captureAt(t, root, "dir/file")
-	if err := os.Rename(parent, filepath.Join(root, "gone")); err != nil {
-		t.Fatalf("move parent aside: %v", err)
-	}
-	mustTargetMkdir(t, parent)
-	second := captureAt(t, root, "dir/file")
-	if pathsafe.SameIdentity(first.Parent(), second.Parent()) ||
-		first.Kind() != KindFile || second.Kind() != KindAbsent {
-		t.Fatal("parent race must be visible through differing parent and target facts")
-	}
-}
-
-func testPreconditionFinalSymlink(t *testing.T) {
-	root := t.TempDir()
-	if err := os.Symlink("referent", filepath.Join(root, "link")); err != nil {
-		t.Fatalf("make symlink: %v", err)
-	}
-	snapshot := captureAt(t, root, "link")
-	if snapshot.Kind() != KindSymlink || snapshot.Payload() != "referent" {
-		t.Fatalf("kind = %v payload %q, want KindSymlink with exact referent", snapshot.Kind(), snapshot.Payload())
-	}
-	if snapshot.Mode()&os.ModeSymlink != 0 {
-		t.Fatal("permission mode must exclude type bits")
-	}
-}
-
-func testPreconditionAbsentTransition(t *testing.T) {
-	root := t.TempDir()
-	first := captureAt(t, root, "file")
-	mustTargetFile(t, filepath.Join(root, "file"), []byte("x"))
-	second := captureAt(t, root, "file")
-	if first.Kind() != KindAbsent || second.Kind() != KindFile {
-		t.Fatal("absent-to-present transition must be visible between captures")
-	}
-}
-
-func testPreconditionModeChange(t *testing.T) {
-	root := t.TempDir()
-	path := filepath.Join(root, "file")
-	mustTargetFile(t, path, []byte("x"))
-	first := captureAt(t, root, "file")
-	if err := os.Chmod(path, 0o600); err != nil {
-		t.Fatalf("chmod target: %v", err)
-	}
-	second := captureAt(t, root, "file")
-	if first.Mode() != 0o644 || second.Mode() != 0o600 {
-		t.Fatal("mode change must be visible while the frozen precondition stays put")
-	}
-}
-
-func testPreconditionIdentityReplacement(t *testing.T) {
-	root := t.TempDir()
-	path := filepath.Join(root, "file")
-	mustTargetFile(t, path, []byte("x"))
-	first := captureAt(t, root, "file")
-	replacement := filepath.Join(root, "replacement")
-	mustTargetFile(t, replacement, []byte("x"))
-	if err := os.Rename(replacement, path); err != nil {
-		t.Fatalf("replace target: %v", err)
-	}
-	second := captureAt(t, root, "file")
-	if pathsafe.SameIdentity(first.Identity(), second.Identity()) {
-		t.Fatal("an identical-content replacement must still expose a new object identity")
-	}
-}
-
-func testPreconditionSymlinkReplacement(t *testing.T) {
-	root := t.TempDir()
-	path := filepath.Join(root, "file")
-	mustTargetFile(t, path, []byte("x"))
-	first := captureAt(t, root, "file")
-	if err := os.Remove(path); err != nil {
-		t.Fatalf("remove target: %v", err)
-	}
-	if err := os.Symlink("elsewhere", path); err != nil {
-		t.Fatalf("replace target with symlink: %v", err)
-	}
-	second := captureAt(t, root, "file")
-	if first.Kind() != KindFile || second.Kind() != KindSymlink || second.Payload() != "elsewhere" {
-		t.Fatal("replacement by symlink must not be read as regular content")
-	}
-}
diff --git a/internal/reconcile/target_snapshot_test.go b/internal/reconcile/target_snapshot_test.go
index 599e005..84a4744 100644
--- a/internal/reconcile/target_snapshot_test.go
+++ b/internal/reconcile/target_snapshot_test.go
@@ -26,6 +26,10 @@ func TestTargetSnapshot(t *testing.T) {
 		{"hard links share identity", testTargetHardLinks},
 		{"missing root", testTargetMissingRoot},
 		{"non-directory root", testTargetFileRoot},
+		{"symlink parent is rejected", testTargetSymlinkParent},
+		{"non-directory parent is rejected", testTargetNonDirectoryParent},
+		{"missing parent is absent", testTargetMissingParent},
+		{"parent replacement is visible", testTargetParentReplacement},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.name, scenario.run)
@@ -205,3 +209,51 @@ func testTargetFileRoot(t *testing.T) {
 		t.Fatal("capture must reject a non-directory root")
 	}
 }
+
+func testTargetSymlinkParent(t *testing.T) {
+	root := t.TempDir()
+	real := filepath.Join(root, "real")
+	mustTargetMkdir(t, real)
+	if err := os.Symlink(real, filepath.Join(root, "link")); err != nil {
+		t.Fatalf("make symlink: %v", err)
+	}
+	if _, err := CaptureTarget(Destination{Root: root, Relative: "link/file.txt"}); err == nil {
+		t.Fatal("capture must reject a symlinked parent component")
+	}
+}
+
+func testTargetNonDirectoryParent(t *testing.T) {
+	root := t.TempDir()
+	mustTargetFile(t, filepath.Join(root, "block"), []byte("x"))
+	if _, err := CaptureTarget(Destination{Root: root, Relative: "block/file.txt"}); err == nil {
+		t.Fatal("capture must reject a non-directory parent component")
+	}
+}
+
+func testTargetMissingParent(t *testing.T) {
+	root := t.TempDir()
+	snapshot := captureAt(t, root, "missing/deep/file.txt")
+	if snapshot.Kind() != KindAbsent {
+		t.Fatalf("kind = %v, want KindAbsent", snapshot.Kind())
+	}
+	if snapshot.Parent().Path() != "" {
+		t.Fatal("missing parents must freeze as the zero parent identity")
+	}
+}
+
+func testTargetParentReplacement(t *testing.T) {
+	root := t.TempDir()
+	parent := filepath.Join(root, "dir")
+	mustTargetMkdir(t, parent)
+	mustTargetFile(t, filepath.Join(parent, "file"), []byte("x"))
+	first := captureAt(t, root, "dir/file")
+	if err := os.Rename(parent, filepath.Join(root, "gone")); err != nil {
+		t.Fatalf("move parent aside: %v", err)
+	}
+	mustTargetMkdir(t, parent)
+	second := captureAt(t, root, "dir/file")
+	if pathsafe.SameIdentity(first.Parent(), second.Parent()) ||
+		first.Kind() != KindFile || second.Kind() != KindAbsent {
+		t.Fatal("parent replacement must expose differing parent and target facts")
+	}
+}