refactor(aura-cli): centralize the sim-optimal RunManifest construction

Three RunReport builders hand-rolled the same RunManifest with identical
commit/seed/broker fields (only params/window varied), drifting
independently. Extract sim_optimal_manifest(params, window) — one source for
the broker label, so #22's per-asset pip work has a single edit point.

crates/aura-cli/src/main.rs

@@ -112,6 +112,21 @@ fn sample_harness() -> (
     (h, rx_eq, rx_ex)
 }
 
+/// Build the sim-optimal `RunManifest`: the engine-external descriptor fields
+/// (commit, seed-free synthetic run, broker label) are constant across the CLI's
+/// built-in harnesses — only `params` and `window` vary. Centralizing the broker
+/// label keeps it a single source (and a single edit point for #22's per-asset
+/// pip work).
+fn sim_optimal_manifest(params: Vec<(String, f64)>, window: (Timestamp, Timestamp)) -> RunManifest {
+    RunManifest {
+        commit: option_env!("AURA_COMMIT").unwrap_or("unknown").to_string(),
+        params,
+        window,
+        seed: 0,
+        broker: "sim-optimal(pip_size=0.0001)".to_string(),
+    }
+}
+
 /// Run the sample harness and fold it into a `RunReport` (drain both sinks →
 /// `f64_field` → `summarize` → pair with a `RunManifest`). Pure and deterministic
 /// (C1): the same build yields the same report.
@@ -131,17 +146,14 @@ fn run_sample() -> RunReport {
     let metrics = summarize(&equity, &exposure);
 
     RunReport {
-        manifest: RunManifest {
-            commit: option_env!("AURA_COMMIT").unwrap_or("unknown").to_string(),
-            params: vec![
+        manifest: sim_optimal_manifest(
+            vec![
                 ("sma_fast".to_string(), 2.0),
                 ("sma_slow".to_string(), 4.0),
                 ("exposure_scale".to_string(), 0.5),
             ],
             window,
-            seed: 0,
-            broker: "sim-optimal(pip_size=0.0001)".to_string(),
-        },
+        ),
         metrics,
     }
 }
@@ -277,13 +289,7 @@ fn sweep_family() -> SweepFamily {
                 .map(|(ps, v)| (ps.name.clone(), scalar_as_param_f64(v)))
                 .collect();
             RunReport {
-                manifest: RunManifest {
-                    commit: option_env!("AURA_COMMIT").unwrap_or("unknown").to_string(),
-                    params,
-                    window,
-                    seed: 0,
-                    broker: "sim-optimal(pip_size=0.0001)".to_string(),
-                },
+                manifest: sim_optimal_manifest(params, window),
                 metrics: summarize(&equity, &exposure),
             }
         })
@@ -462,18 +468,15 @@ fn run_macd() -> RunReport {
     let metrics = summarize(&equity, &exposure);
 
     RunReport {
-        manifest: RunManifest {
-            commit: option_env!("AURA_COMMIT").unwrap_or("unknown").to_string(),
-            params: vec![
+        manifest: sim_optimal_manifest(
+            vec![
                 ("ema_fast".to_string(), 2.0),
                 ("ema_slow".to_string(), 4.0),
                 ("ema_signal".to_string(), 3.0),
                 ("exposure_scale".to_string(), 0.5),
             ],
             window,
-            seed: 0,
-            broker: "sim-optimal(pip_size=0.0001)".to_string(),
-        },
+        ),
         metrics,
     }
 }