ignore kleppmann_trace test — 10+ min, 12GB RAM

Marked #[ignore] so cargo test skips it by default. Run manually with
--ignored flag when needed for benchmarking.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/bft-json-crdt/tests/kleppmann_trace.rs

@@ -38,7 +38,10 @@ fn get_trace() -> Trace {
 /// Really large test to run Martin Kleppmann's
 /// editing trace over his paper
 /// Data source: https://github.com/automerge/automerge-perf
+// Commented out: takes 10+ minutes and 12GB+ RAM. Run manually with:
+//   cargo test --package bft-json-crdt --test kleppmann_trace -- --ignored
 #[test]
+#[ignore]
 fn test_editing_trace() {
     let t = get_trace();
     let mut list = ListCrdt::<char>::new(make_author(1), vec![]);