Add reconcile state planning core

internal/state/distributor_test.go

@@ -61,6 +61,38 @@ func TestParseValidStateWithLinks(t *testing.T) {
 	}
 }
 
+func TestRemoveMissingOutputs(t *testing.T) {
+	state, err := Parse([]byte(validStateJSON(t)))
+	if err != nil {
+		t.Fatalf("Parse() error = %v", err)
+	}
+	state.Outputs = append(state.Outputs, OutputFile{
+		Path:       "summary.txt",
+		Kind:       OutputKindSource,
+		SourcePath: "summary.txt",
+		SHA256:     "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+		Size:       10,
+		CreatedAt:  state.CreatedAt,
+		UpdatedAt:  state.UpdatedAt,
+	})
+
+	next, changed := RemoveMissingOutputs(state, []string{"summary.txt"})
+	if !changed {
+		t.Fatal("RemoveMissingOutputs() changed = false, want true")
+	}
+	if got, want := ManagedOutputPaths(next), []string{"report.md"}; strings.Join(got, ",") != strings.Join(want, ",") {
+		t.Fatalf("paths = %#v, want %#v", got, want)
+	}
+
+	unchanged, changed := RemoveMissingOutputs(next, []string{"missing.txt"})
+	if changed {
+		t.Fatal("RemoveMissingOutputs() changed = true, want false")
+	}
+	if got, want := ManagedOutputPaths(unchanged), []string{"report.md"}; strings.Join(got, ",") != strings.Join(want, ",") {
+		t.Fatalf("unchanged paths = %#v, want %#v", got, want)
+	}
+}
+
 func TestParseNormalizesPublishedAtOffset(t *testing.T) {
 	body := strings.Replace(validStateJSON(t), `"published_at": "2026-05-30T11:12:00Z"`, `"published_at": "2026-05-30T13:12:00+02:00"`, 1)
 	state, err := Parse([]byte(body))