Ψ-W1-T1 second-round remediation: ±1-frame bounds tolerance, self-cleanup a refused render, hedge two unverified render-source inferences

Loosens the exact-bounds gate against REAPER's edge rounding; deletes the bytes a BoundsMismatch refusal writes, per prune_fs's self-cleanup carve-out.

tests/test_track_topology.cpp

@@ -70,6 +70,15 @@ static void testUnterminatedFolderSwallowsTheRest() {
     CHECK(sameIndices(directChildIndices(depths, 0), {1, 2}));
 }
 
+static void testSiblingFolderAfterParentClosesIsNotIncluded() {
+    // 0: folder parent, 1: child, 2: last child (closes it). 3: an unrelated sibling
+    // folder that opens AFTER track 0's folder has already closed, 4: its child, 5:
+    // its last child. A walk that fails to stop at track 0's own close would keep
+    // consuming and wrongly pull the sibling's children in too.
+    const std::vector<int> depths{1, 0, -1, 1, 0, -1};
+    CHECK(sameIndices(directChildIndices(depths, 0), {1, 2}));
+}
+
 int main() {
     testFlatProjectHasNoChildren();
     testFolderParentReturnsItsDirectChildren();
@@ -77,6 +86,7 @@ int main() {
     testMultiLevelCloseEndsTheOuterFolderToo();
     testNonFolderAndOutOfRangeReturnEmpty();
     testUnterminatedFolderSwallowsTheRest();
+    testSiblingFolderAfterParentClosesIsNotIncluded();
 
     if (g_fail == 0) std::printf("track_topology: all tests passed\n");
     return g_fail == 0 ? 0 : 1;