test(cli): RED — dissolved --trace requests the unproducible net tap (#240)

The generated sugar campaigns carry an empty cost section by construction,
so net_r_equity can never be produced on the sweep/walkforward --trace path;
requesting it makes the executor print a remedy (add a cost block to the
campaign document) unreachable from the invoked verb.

refs #240

crates/aura-cli/src/verb_sugar.rs

@@ -953,6 +953,40 @@ mod tests {
         assert_eq!(g.campaign.presentation.persist_taps, want);
     }
 
+    /// Property (#240): a dissolved `--trace` invocation's generated campaign
+    /// requests only the taps its own document can produce. Every generated
+    /// sugar campaign carries an empty cost section (`cost: vec![]`) by
+    /// construction, so the net-channel tap `net_r_equity` is unproducible and
+    /// must be excluded — the requested set is the tap vocabulary MINUS the net
+    /// channel, concretely `["equity", "exposure", "r_equity"]`. Pinned for
+    /// both trace-bearing translators (sweep + walkforward), which share the
+    /// one `persist_taps_from` seam; without this the executor later prints an
+    /// unreachable "add a cost block to the campaign document" remedy for a tap
+    /// the generator knowingly ordered but its own document cannot produce.
+    #[test]
+    fn dissolved_trace_requests_only_producible_taps_excluding_the_net_channel() {
+        let want =
+            vec!["equity".to_string(), "exposure".to_string(), "r_equity".to_string()];
+
+        let sax = axes();
+        let mut si = inv(&sax, "probe", &["GER40"], None, "{\"bp\":1}");
+        si.trace = true;
+        let s = translate_sweep(&si).unwrap();
+        assert_eq!(
+            s.campaign.presentation.persist_taps, want,
+            "sweep --trace must request only producible taps: the generated cost section is empty, so net_r_equity is unproducible and must be dropped"
+        );
+
+        let wax = wf_axes();
+        let mut wi = inv(&wax, "walkforward", &["GER40"], Some(VolStop { length: 14, k: 2.0 }), "{\"bp\":1}");
+        wi.trace = true;
+        let w = translate_walkforward(&wi, "sqn_normalized", WF_W, SelectRule::Argmax).unwrap();
+        assert_eq!(
+            w.campaign.presentation.persist_taps, want,
+            "walkforward --trace must request only producible taps: the generated cost section is empty, so net_r_equity is unproducible and must be dropped"
+        );
+    }
+
     #[test]
     fn translate_walkforward_diverging_regimes_do_not_collide_content_ids() {
         let ax = wf_axes();