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>

server/src/db/mod.rs

@@ -1,3 +1,6 @@
+#[allow(unexpected_cfgs)]
+pub mod crdt;
+
 /// SQLite shadow-write layer for pipeline state.
 ///
 /// All filesystem pipeline operations (move_story_to_X etc.) remain authoritative.