Q-W1 code-review follow-ups: restore 104 trailing newlines, relocate reasampler_uid.h to core/wire, drop ext_keys namespaces shim, add slot_map_tests, golden serialize literals for 4 modules, namespaces.h/pragma-once ordering sweep. 60/60 green.

tests/test_view_mode_model.cpp

@@ -56,6 +56,20 @@ static int flagValue(const TrackPlan& p, Flag f) {
     return -999;  // sentinel: flag absent
 }
 
+// Golden byte-literal (Q-W1 follow-up): pins the EXACT serialized bytes for the
+// default-seeded model (Arrange + Design, no membership), not just self-
+// consistent re-serialization — a format drift that both writer and reader
+// agree on would slip past the round-trip tests but not this. The format is
+// frozen as-shipped; the literal below is the captured current output.
+static void testSerializeGoldenLiteral() {
+    ViewModeModel vm;
+    CHECK(vm.serialize() ==
+          "{\"version\":1,\"activeMode\":\"arrange\",\"modes\":[{\"id\":\"arrange\","
+          "\"displayName\":\"Arrange\",\"ordinal\":0},{\"id\":\"design\","
+          "\"displayName\":\"Design\",\"ordinal\":1}],\"membership\":[],"
+          "\"snapshots\":[],\"lanes\":[]}");
+}
+
 // -- 1. N-mode proven --------------------------------------------------------
 
 static void testNModeRegistryAndMembership() {
@@ -1787,6 +1801,7 @@ static void testLaneMalformedJson() {
 }
 
 int main() {
+    testSerializeGoldenLiteral();
     testNModeRegistryAndMembership();
     testParentDerivationMultiMode();
     testParentOwnMembershipVisibility();