feat(cli,docs): ship the ganged open examples + document the gang construct (#61 tasks 7-8)

The two open examples now expose their author-intended single knobs — the
closed builders always bound these pairs to one value by hand; the open forms
falsely offered them as independent axes:
- r_breakout_open: channel_hi.length + channel_lo.length -> channel_length
  (the Donchian channel is structurally ONE parameter)
- r_meanrev_open: mean_window.length + var_window.length -> window; the band
  factor stays an independent axis
Regenerated via the emitters (never hand-edited); the closed examples are
byte-unchanged. The carve builders gang in the open branch only.

Test migration: the two axis-namespace pins, five --real e2e invocations
(single gang axis, the 10,20 diagonal for the campaign pair — the mismatched
20,40/10,20 grid was exactly the configuration space the gang retires), and
the param_stability row counts (4 -> 3). The r-sma walkforward golden anchor
is untouched (it never swept a ganged pair).

Docs: authoring-guide gains the seventh op + the third param state
(open/bound/ganged) + the gang wrap note; README op list + Axis concept;
glossary gang entry; ledger C24 records the gang verb and the pre-ship
Tier-2 dormancy (no format-version bump while no out-of-repo reader exists).

Verified: full workspace suite 1104/0 (--real e2e included, local data
present), clippy -D warnings clean, cargo doc clean; live acceptance:
introspect --params prints channel_length:I64 alone / window:I64 +
band.factor:F64.

closes #61

crates/aura-cli/examples/r_breakout_open.json

@@ -1 +1 @@
-{"format_version":1,"blueprint":{"name":"r_breakout_signal","nodes":[{"primitive":{"type":"Delay","bound":[{"pos":0,"name":"lag","kind":"I64","value":{"I64":1}}]}},{"primitive":{"type":"RollingMax","name":"channel_hi"}},{"primitive":{"type":"RollingMin","name":"channel_lo"}},{"primitive":{"type":"Gt"}},{"primitive":{"type":"Gt"}},{"primitive":{"type":"Latch"}},{"primitive":{"type":"Latch"}},{"primitive":{"type":"Sub"}}],"edges":[{"from":0,"to":1,"slot":0,"from_field":0},{"from":0,"to":2,"slot":0,"from_field":0},{"from":1,"to":3,"slot":1,"from_field":0},{"from":2,"to":4,"slot":0,"from_field":0},{"from":3,"to":5,"slot":0,"from_field":0},{"from":4,"to":5,"slot":1,"from_field":0},{"from":4,"to":6,"slot":0,"from_field":0},{"from":3,"to":6,"slot":1,"from_field":0},{"from":5,"to":7,"slot":0,"from_field":0},{"from":6,"to":7,"slot":1,"from_field":0}],"input_roles":[{"name":"price","targets":[{"node":0,"slot":0},{"node":3,"slot":0},{"node":4,"slot":1}],"source":"F64"}],"output":[{"node":7,"field":0,"name":"bias"}]}}
+{"format_version":1,"blueprint":{"name":"r_breakout_signal","nodes":[{"primitive":{"type":"Delay","bound":[{"pos":0,"name":"lag","kind":"I64","value":{"I64":1}}]}},{"primitive":{"type":"RollingMax","name":"channel_hi"}},{"primitive":{"type":"RollingMin","name":"channel_lo"}},{"primitive":{"type":"Gt"}},{"primitive":{"type":"Gt"}},{"primitive":{"type":"Latch"}},{"primitive":{"type":"Latch"}},{"primitive":{"type":"Sub"}}],"edges":[{"from":0,"to":1,"slot":0,"from_field":0},{"from":0,"to":2,"slot":0,"from_field":0},{"from":1,"to":3,"slot":1,"from_field":0},{"from":2,"to":4,"slot":0,"from_field":0},{"from":3,"to":5,"slot":0,"from_field":0},{"from":4,"to":5,"slot":1,"from_field":0},{"from":4,"to":6,"slot":0,"from_field":0},{"from":3,"to":6,"slot":1,"from_field":0},{"from":5,"to":7,"slot":0,"from_field":0},{"from":6,"to":7,"slot":1,"from_field":0}],"input_roles":[{"name":"price","targets":[{"node":0,"slot":0},{"node":3,"slot":0},{"node":4,"slot":1}],"source":"F64"}],"output":[{"node":7,"field":0,"name":"bias"}],"gangs":[{"name":"channel_length","kind":"I64","members":[{"node":1,"pos":0,"name":"length"},{"node":2,"pos":0,"name":"length"}]}]}}

crates/aura-cli/examples/r_meanrev_open.json

@@ -1 +1 @@
-{"format_version":1,"blueprint":{"name":"r_meanrev_signal","nodes":[{"primitive":{"type":"EMA","name":"mean_window"}},{"primitive":{"type":"Sub"}},{"primitive":{"type":"Mul"}},{"primitive":{"type":"EMA","name":"var_window"}},{"primitive":{"type":"Sqrt"}},{"primitive":{"type":"Scale","name":"band"}},{"primitive":{"type":"Add"}},{"primitive":{"type":"Sub"}},{"primitive":{"type":"Gt"}},{"primitive":{"type":"Gt"}},{"primitive":{"type":"Latch"}},{"primitive":{"type":"Latch"}},{"primitive":{"type":"Sub"}}],"edges":[{"from":0,"to":1,"slot":1,"from_field":0},{"from":1,"to":2,"slot":0,"from_field":0},{"from":1,"to":2,"slot":1,"from_field":0},{"from":2,"to":3,"slot":0,"from_field":0},{"from":3,"to":4,"slot":0,"from_field":0},{"from":4,"to":5,"slot":0,"from_field":0},{"from":0,"to":6,"slot":0,"from_field":0},{"from":5,"to":6,"slot":1,"from_field":0},{"from":0,"to":7,"slot":0,"from_field":0},{"from":5,"to":7,"slot":1,"from_field":0},{"from":6,"to":8,"slot":1,"from_field":0},{"from":7,"to":9,"slot":0,"from_field":0},{"from":8,"to":10,"slot":0,"from_field":0},{"from":9,"to":10,"slot":1,"from_field":0},{"from":9,"to":11,"slot":0,"from_field":0},{"from":8,"to":11,"slot":1,"from_field":0},{"from":11,"to":12,"slot":0,"from_field":0},{"from":10,"to":12,"slot":1,"from_field":0}],"input_roles":[{"name":"price","targets":[{"node":0,"slot":0},{"node":1,"slot":0},{"node":8,"slot":0},{"node":9,"slot":1}],"source":"F64"}],"output":[{"node":12,"field":0,"name":"bias"}]}}
+{"format_version":1,"blueprint":{"name":"r_meanrev_signal","nodes":[{"primitive":{"type":"EMA","name":"mean_window"}},{"primitive":{"type":"Sub"}},{"primitive":{"type":"Mul"}},{"primitive":{"type":"EMA","name":"var_window"}},{"primitive":{"type":"Sqrt"}},{"primitive":{"type":"Scale","name":"band"}},{"primitive":{"type":"Add"}},{"primitive":{"type":"Sub"}},{"primitive":{"type":"Gt"}},{"primitive":{"type":"Gt"}},{"primitive":{"type":"Latch"}},{"primitive":{"type":"Latch"}},{"primitive":{"type":"Sub"}}],"edges":[{"from":0,"to":1,"slot":1,"from_field":0},{"from":1,"to":2,"slot":0,"from_field":0},{"from":1,"to":2,"slot":1,"from_field":0},{"from":2,"to":3,"slot":0,"from_field":0},{"from":3,"to":4,"slot":0,"from_field":0},{"from":4,"to":5,"slot":0,"from_field":0},{"from":0,"to":6,"slot":0,"from_field":0},{"from":5,"to":6,"slot":1,"from_field":0},{"from":0,"to":7,"slot":0,"from_field":0},{"from":5,"to":7,"slot":1,"from_field":0},{"from":6,"to":8,"slot":1,"from_field":0},{"from":7,"to":9,"slot":0,"from_field":0},{"from":8,"to":10,"slot":0,"from_field":0},{"from":9,"to":10,"slot":1,"from_field":0},{"from":9,"to":11,"slot":0,"from_field":0},{"from":8,"to":11,"slot":1,"from_field":0},{"from":11,"to":12,"slot":0,"from_field":0},{"from":10,"to":12,"slot":1,"from_field":0}],"input_roles":[{"name":"price","targets":[{"node":0,"slot":0},{"node":1,"slot":0},{"node":8,"slot":0},{"node":9,"slot":1}],"source":"F64"}],"output":[{"node":12,"field":0,"name":"bias"}],"gangs":[{"name":"window","kind":"I64","members":[{"node":0,"pos":0,"name":"length"},{"node":3,"pos":0,"name":"length"}]}]}}

crates/aura-cli/src/main.rs

@@ -1831,8 +1831,8 @@ const R_BREAKOUT_CHANNEL: i64 = 3;
 /// as blueprint data (#159 cut 2). The signal computation matches the retired fused
 /// builder's leg (same nodes, same wiring); the pip/R harness is the generic
 /// `wrap_r` wrapper, not part of the signal. `channel = Some(n)` binds both rolling
-/// nodes (closed); `None` leaves them open (two sweep axes — per-node exposure;
-/// ganging one knob into both is the separate #61). This carve has no production
+/// nodes (closed); `None` leaves them open, ganged into the single `channel_length`
+/// knob (#61) — the channel is structurally ONE parameter. This carve has no production
 /// (non-test) caller — it is exercised only by the regeneration + proof tests below;
 /// production code loads the shipped JSON, not this builder — hence `#[cfg(test)]`.
 #[cfg(test)]
@@ -1847,6 +1847,9 @@ fn r_breakout_signal(channel: Option<i64>) -> Composite {
     }
     let mx = g.add(mx_b);
     let mn = g.add(mn_b);
+    if channel.is_none() {
+        g.gang("channel_length", [mx.param("length"), mn.param("length")]);
+    }
     let gt_up = g.add(Gt::builder());
     let gt_down = g.add(Gt::builder());
     let up_latch = g.add(Latch::builder());
@@ -1869,8 +1872,9 @@ fn r_breakout_signal(channel: Option<i64>) -> Composite {
 }
 
 /// The EWMA window for the canonical closed r_meanrev example (ganged mean/var Ema
-/// length). Single source for the emitter and the proof tests that must all agree
-/// with the baked `examples/r_meanrev.json`.
+/// length; the open form gangs them structurally via the single `window` knob, #61).
+/// Single source for the emitter and the proof tests that must all agree with the
+/// baked `examples/r_meanrev.json`.
 #[cfg(test)]
 const R_MEANREV_WINDOW: i64 = 3;
 
@@ -1898,6 +1902,9 @@ fn r_meanrev_signal(window: Option<i64>, band_k: Option<f64>) -> Composite {
     let dev = g.add(Sub::builder()); // price - mean
     let sq = g.add(Mul::builder()); // dev * dev
     let var = g.add(var_b); // EWMA variance
+    if window.is_none() {
+        g.gang("window", [mean.param("length"), var.param("length")]);
+    }
     let sigma = g.add(Sqrt::builder());
     let mut band_b = Scale::builder().named("band");
     if let Some(k) = band_k {

crates/aura-cli/tests/cli_run.rs

@@ -1739,7 +1739,7 @@ fn generalize_real_e2e_pins_the_exact_current_grade() {
 /// `r_sma_open.json`, so a regression that silently special-cased r-sma paths
 /// back in (e.g. resolving axes against a hardcoded `sma_signal.*` namespace)
 /// would ship green there while breaking every other blueprint. This runs the
-/// unrelated r-breakout candidate (`channel_hi`/`channel_lo` axes, no
+/// unrelated r-breakout candidate (the ganged `channel_length` axis, no
 /// `sma_signal` node in sight) end-to-end and asserts a well-formed two-
 /// instrument grade. Gated on the shared GER40/USDJPY Sept-2024 archive; skips
 /// cleanly on a data refusal.
@@ -1752,8 +1752,7 @@ fn generalize_grades_a_non_r_sma_blueprint() {
     let out = std::process::Command::new(env!("CARGO_BIN_EXE_aura"))
         .args([
             "generalize", &fixture, "--real", "GER40,USDJPY",
-            "--axis", "r_breakout_signal.channel_hi.length=20",
-            "--axis", "r_breakout_signal.channel_lo.length=20",
+            "--axis", "r_breakout_signal.channel_length=20",
             "--stop-length", "14", "--stop-k", "2.0",
             "--from", FROM_MS, "--to", TO_MS,
         ])
@@ -1848,9 +1847,9 @@ fn walkforward_real_e2e_pins_the_exact_current_grade() {
 /// namespace (e.g. in `walkforward_summary_json_from_reports`'s per-axis
 /// `raw_matches_wrapped` search) would ship green there while breaking every
 /// other blueprint. This runs the unrelated r-breakout candidate
-/// (`channel_hi`/`channel_lo` axes, no `sma_signal` node in sight) end-to-end
+/// (the ganged `channel_length` axis, no `sma_signal` node in sight) end-to-end
 /// and asserts a well-formed multi-window summary whose `param_stability` has
-/// exactly one entry per bound axis (2 blueprint axes + the 2 stop columns).
+/// exactly one entry per bound axis (1 ganged blueprint axis + the 2 stop columns).
 /// The window count (9) is roller/data-derived, not strategy-derived, so it is
 /// pinned exactly against the same GER40 2025 span the r-sma anchor uses.
 /// Gated on the shared GER40 archive; skips cleanly on a data refusal.
@@ -1863,8 +1862,7 @@ fn walkforward_dissolves_a_non_r_sma_blueprint() {
     let out = std::process::Command::new(env!("CARGO_BIN_EXE_aura"))
         .args([
             "walkforward", &fixture, "--real", "GER40",
-            "--axis", "r_breakout_signal.channel_hi.length=10,20",
-            "--axis", "r_breakout_signal.channel_lo.length=10,20",
+            "--axis", "r_breakout_signal.channel_length=10,20",
             "--stop-length", "14", "--stop-k", "2.0",
             "--from", FROM_MS, "--to", TO_MS,
         ])
@@ -1891,7 +1889,7 @@ fn walkforward_dissolves_a_non_r_sma_blueprint() {
     assert_eq!(wf["windows"].as_u64(), Some(9), "window count (data/roller-derived): {grade_line}");
     assert!(wf["oos_r"]["n_trades"].as_u64().is_some(), "pooled OOS trade count present: {grade_line}");
     let ps = wf["param_stability"].as_array().expect("param_stability is an array");
-    assert_eq!(ps.len(), 4, "one entry per bound axis (channel_hi, channel_lo, stop_length, stop_k): {grade_line}");
+    assert_eq!(ps.len(), 3, "one entry per bound axis (channel_length, stop_length, stop_k): {grade_line}");
 }
 
 /// Fork A: the dissolved walkforward binds the stop as a single risk regime, so a
@@ -3882,7 +3880,7 @@ fn mc_r_bootstrap_real_e2e_pins_the_exact_current_grade() {
 /// exercises `r_sma_open.json`; a regression that silently special-cased the
 /// pipeline's axis lookup back to a hardcoded `sma_signal.*` namespace would
 /// ship green there while breaking every other blueprint. This runs the
-/// unrelated r-breakout candidate (`channel_hi`/`channel_lo` axes, no
+/// unrelated r-breakout candidate (the ganged `channel_length` axis, no
 /// `sma_signal` node in sight) end-to-end and asserts a well-formed
 /// `mc_r_bootstrap` grade: the argv-echoed knobs (`block_len`/`n_resamples`)
 /// pin exactly, `n_trades`/`e_r.mean`/`prob_le_zero` are asserted present and
@@ -3898,8 +3896,7 @@ fn mc_dissolves_a_non_r_sma_blueprint() {
     let out = std::process::Command::new(env!("CARGO_BIN_EXE_aura"))
         .args([
             "mc", &fixture, "--real", "GER40",
-            "--axis", "r_breakout_signal.channel_hi.length=10,20",
-            "--axis", "r_breakout_signal.channel_lo.length=10,20",
+            "--axis", "r_breakout_signal.channel_length=10,20",
             "--stop-length", "14", "--stop-k", "2.0",
             "--block-len", "5", "--resamples", "1000", "--seed", "42",
             "--from", FROM_MS, "--to", TO_MS,
@@ -4175,8 +4172,7 @@ fn walkforward_campaign_runs_an_arbitrary_blueprint() {
     let out = std::process::Command::new(env!("CARGO_BIN_EXE_aura"))
         .args([
             "walkforward", &fixture, "--real", "GER40",
-            "--axis", "r_breakout_signal.channel_hi.length=20,40",
-            "--axis", "r_breakout_signal.channel_lo.length=10,20",
+            "--axis", "r_breakout_signal.channel_length=10,20",
             "--stop-length", "3", "--stop-k", "2.0",
             "--from", FROM_MS, "--to", TO_MS,
         ])
@@ -4207,9 +4203,9 @@ fn walkforward_campaign_runs_an_arbitrary_blueprint() {
     let v: serde_json::Value = serde_json::from_str(grade_line).expect("summary line parses as JSON");
     let wf = &v["walkforward"];
     assert!(wf["windows"].as_u64().is_some_and(|w| w >= 1), "at least one window: {grade_line}");
-    // param_stability rows: channel_hi, channel_lo, stop_length, stop_k.
+    // param_stability rows: channel_length, stop_length, stop_k.
     let ps = wf["param_stability"].as_array().expect("param_stability is an array");
-    assert_eq!(ps.len(), 4, "two channel axes + the stop pair: {grade_line}");
+    assert_eq!(ps.len(), 3, "one ganged channel axis + the stop pair: {grade_line}");
 }
 
 /// #220 weld-gone proof for mc: the R-bootstrap pipeline runs the same
@@ -4227,8 +4223,7 @@ fn mc_campaign_runs_an_arbitrary_blueprint() {
     let out = std::process::Command::new(env!("CARGO_BIN_EXE_aura"))
         .args([
             "mc", &fixture, "--real", "GER40",
-            "--axis", "r_breakout_signal.channel_hi.length=20,40",
-            "--axis", "r_breakout_signal.channel_lo.length=10,20",
+            "--axis", "r_breakout_signal.channel_length=10,20",
             "--stop-length", "3", "--stop-k", "2.0",
             "--block-len", "5", "--resamples", "100", "--seed", "7",
             "--from", FROM_MS, "--to", TO_MS,
@@ -4263,8 +4258,9 @@ fn mc_campaign_runs_an_arbitrary_blueprint() {
 }
 
 /// #220 weld-gone proof for generalize: one mean-reversion candidate graded
-/// across two instruments — three axes with names the CLI has never heard of,
-/// including an F64 axis. Gated on the GER40/USDJPY Sept-2024 archive.
+/// across two instruments — two axes with names the CLI has never heard of —
+/// one ganged I64 window and an independent F64 band. Gated on the GER40/USDJPY
+/// Sept-2024 archive.
 #[test]
 fn generalize_campaign_runs_an_arbitrary_blueprint() {
     if !local_data_present() {
@@ -4276,8 +4272,7 @@ fn generalize_campaign_runs_an_arbitrary_blueprint() {
     let out = std::process::Command::new(env!("CARGO_BIN_EXE_aura"))
         .args([
             "generalize", &fixture, "--real", "GER40,USDJPY",
-            "--axis", "r_meanrev_signal.mean_window.length=20",
-            "--axis", "r_meanrev_signal.var_window.length=20",
+            "--axis", "r_meanrev_signal.window=20",
             "--axis", "r_meanrev_signal.band.factor=2.0",
             "--stop-length", "3", "--stop-k", "2.0",
             "--from", GER40_SEPT2024_FROM_MS, "--to", GER40_SEPT2024_TO_MS,

crates/aura-cli/tests/graph_construct.rs

@@ -744,7 +744,8 @@ fn shipped_r_breakout_example_is_genuinely_closed() {
 }
 
 /// Property (#159 cut 2): the shipped open example (`examples/r_breakout_open.json`)
-/// lists its two channel axes, in lowering order (per-node exposure; ganging is #61).
+/// lists its ONE ganged channel axis (#61: the two rolling windows are structurally
+/// one knob).
 #[test]
 fn shipped_r_breakout_open_example_lists_its_axis_namespace() {
     let dir = temp_cwd("r-breakout-example-open-params");
@@ -752,8 +753,47 @@ fn shipped_r_breakout_open_example_lists_its_axis_namespace() {
         run_in(&dir, &["graph", "introspect", "--params", &example("r_breakout_open.json")]);
     assert_eq!(code, Some(0), "stdout: {stdout} stderr: {stderr}");
     assert_eq!(
-        stdout, "channel_hi.length:I64\nchannel_lo.length:I64\n",
-        "the raw open params, in order, from the public gallery copy"
+        stdout, "channel_length:I64\n",
+        "the ganged channel knob — one public axis for the two rolling windows (#61)"
+    );
+}
+
+/// Property (#61 + #159 cut 2): binding the shipped open example's ganged
+/// `channel_length` axis through the REAL `aura sweep` CLI pipeline (argv ->
+/// `parse_axes` -> `compile_with_cells`'s gang expansion) reproduces the exact
+/// metrics of running the shipped CLOSED example, whose `channel_hi`/
+/// `channel_lo` are separately hardwired to the same value. The equivalence
+/// between a gang and its member-bound twin is already pinned at the builder/
+/// engine level (aura-engine's `gang_e2e.rs`, and this crate's
+/// `r_breakout_example_loaded_runs_identically_to_the_carved_signal`, which
+/// calls `run_signal_r` directly); this instead drives the actual public
+/// binary end-to-end on the actual shipped files, so a regression in the
+/// CLI's own axis-name resolution or grid-point binding (e.g. silently
+/// treating the gang as an unbound param, or fanning the value to only one
+/// member) would be caught here even if the internal builder-level
+/// equivalence still holds.
+#[test]
+fn shipped_r_breakout_open_gang_axis_matches_the_closed_example() {
+    let closed_dir = temp_cwd("r-breakout-gang-axis-closed");
+    let (closed_stdout, closed_stderr, closed_code) = run_in(&closed_dir, &["run", &example("r_breakout.json")]);
+    assert_eq!(closed_code, Some(0), "closed run stderr: {closed_stderr}");
+    let closed: serde_json::Value =
+        serde_json::from_str(closed_stdout.trim()).expect("closed run report parses as JSON");
+
+    let sweep_dir = temp_cwd("r-breakout-gang-axis-sweep");
+    let (sweep_stdout, sweep_stderr, sweep_code) = run_in(
+        &sweep_dir,
+        &["sweep", &example("r_breakout_open.json"), "--axis", "r_breakout_signal.channel_length=3"],
+    );
+    assert_eq!(sweep_code, Some(0), "sweep stderr: {sweep_stderr}");
+    let lines: Vec<&str> = sweep_stdout.lines().collect();
+    assert_eq!(lines.len(), 1, "one grid point for a single-value axis: {sweep_stdout}");
+    let member: serde_json::Value = serde_json::from_str(lines[0]).expect("member line parses as JSON");
+
+    assert_eq!(
+        member["report"]["metrics"], closed["metrics"],
+        "channel_length=3, bound via the real sweep CLI, must fan out to both channel_hi \
+         and channel_lo identically to the closed example's hardwired channel=3"
     );
 }
 
@@ -777,8 +817,45 @@ fn shipped_r_meanrev_open_example_lists_its_axis_namespace() {
         run_in(&dir, &["graph", "introspect", "--params", &example("r_meanrev_open.json")]);
     assert_eq!(code, Some(0), "stdout: {stdout} stderr: {stderr}");
     assert_eq!(
-        stdout, "mean_window.length:I64\nvar_window.length:I64\nband.factor:F64\n",
-        "the raw open params, in lowering order"
+        stdout, "window:I64\nband.factor:F64\n",
+        "the ganged EWMA window + the independent band knob, in lowering order"
+    );
+}
+
+/// Property (#61 + #159 cut 3): a sweep over TWO axes at once — the ganged
+/// `window` knob (fusing `mean_window.length`/`var_window.length`) alongside
+/// the independent, un-ganged `band.factor` knob — binds both correctly
+/// through the real CLI grid, matching the shipped closed example's hardwired
+/// window=3/band=2.0. This is a distinct risk from the r_breakout gang test
+/// (a lone gang axis): a mis-scoped gang-expansion map that shifts sibling
+/// param positions could silently mis-bind the co-present un-ganged axis
+/// instead (or vice-versa) even though each axis alone still resolves.
+#[test]
+fn shipped_r_meanrev_open_gang_plus_plain_axis_matches_the_closed_example() {
+    let closed_dir = temp_cwd("r-meanrev-gang-axis-closed");
+    let (closed_stdout, closed_stderr, closed_code) = run_in(&closed_dir, &["run", &example("r_meanrev.json")]);
+    assert_eq!(closed_code, Some(0), "closed run stderr: {closed_stderr}");
+    let closed: serde_json::Value =
+        serde_json::from_str(closed_stdout.trim()).expect("closed run report parses as JSON");
+
+    let sweep_dir = temp_cwd("r-meanrev-gang-axis-sweep");
+    let (sweep_stdout, sweep_stderr, sweep_code) = run_in(
+        &sweep_dir,
+        &[
+            "sweep", &example("r_meanrev_open.json"),
+            "--axis", "r_meanrev_signal.window=3",
+            "--axis", "r_meanrev_signal.band.factor=2.0",
+        ],
+    );
+    assert_eq!(sweep_code, Some(0), "sweep stderr: {sweep_stderr}");
+    let lines: Vec<&str> = sweep_stdout.lines().collect();
+    assert_eq!(lines.len(), 1, "one grid point for two single-value axes: {sweep_stdout}");
+    let member: serde_json::Value = serde_json::from_str(lines[0]).expect("member line parses as JSON");
+
+    assert_eq!(
+        member["report"]["metrics"], closed["metrics"],
+        "window=3 (ganged) + band.factor=2.0 (plain), bound via the real sweep CLI, must \
+         match the closed example's hardwired window=3/band=2.0"
     );
 }