feat(cli): verb_sugar translator — argv to generated campaign documents (#210 T3)

The pure half of the sweep re-cut: translate_sweep maps a real-data
blueprint-sweep invocation (axes, name, symbol, window, canonical
blueprint bytes) to a selection-free single-stage process document plus
a campaign document carrying exactly the invocation's intent (seed 0 —
no stage consumes it — so identical invocations dedupe onto identical
content ids); register_generated puts both into the content-addressed
stores. Unit tests pin determinism, name flow, mixed-kind-axis refusal,
and that generated documents pass intrinsic validation + preflight.

Dead-code-allowed until the dispatch rewire wires the module (next
task removes the bridge attribute). Plan bytes reconciled with three
necessary deviations the spec gate surfaced: derive(Debug) for
unwrap_err, ScalarKind lives in aura_core, and 'gen' is reserved in
edition 2024.

refs #210

docs/plans/sweep-dissolution.md

@@ -529,14 +529,15 @@ Create `crates/aura-cli/src/verb_sugar.rs`:
 
 use std::collections::BTreeMap;
 
-use aura_core::Scalar;
+use aura_core::{Scalar, ScalarKind};
 use aura_research::{
     campaign_to_json, content_id_of, process_to_json, Axis, CampaignDoc, DataSection, DocKind,
-    DocRef, Presentation, ProcessDoc, ProcessRef, ScalarKind, StageBlock, StrategyEntry, Window,
+    DocRef, Presentation, ProcessDoc, ProcessRef, StageBlock, StrategyEntry, Window,
     FORMAT_VERSION,
 };
 
 /// The two generated documents of one dissolved-verb invocation.
+#[derive(Debug)] // unwrap_err() in the unit tests needs T: Debug
 pub(crate) struct GeneratedSweep {
     pub process: ProcessDoc,
     pub campaign: CampaignDoc,
@@ -622,10 +623,12 @@ pub(crate) fn translate_sweep(
 /// Returns `(process_id, campaign_id)`.
 pub(crate) fn register_generated(
     reg: &aura_registry::Registry,
-    gen: &GeneratedSweep,
+    generated: &GeneratedSweep, // `gen` is a reserved keyword in edition 2024
 ) -> Result<(String, String), String> {
-    let process_id = reg.put_process(&process_to_json(&gen.process)).map_err(|e| e.to_string())?;
-    let campaign_id = reg.put_campaign(&campaign_to_json(&gen.campaign)).map_err(|e| e.to_string())?;
+    let process_id =
+        reg.put_process(&process_to_json(&generated.process)).map_err(|e| e.to_string())?;
+    let campaign_id =
+        reg.put_campaign(&campaign_to_json(&generated.campaign)).map_err(|e| e.to_string())?;
     Ok((process_id, campaign_id))
 }
 ```
@@ -804,6 +807,10 @@ pub(crate) fn run_sweep_sugar(
 
 - [ ] **Step 3: Dispatch rewire — the real arm routes through sugar**
 
+First, remove the temporary `#![allow(dead_code)]` inner attribute (and its
+two comment lines) near the top of `crates/aura-cli/src/verb_sugar.rs` — the
+module gains its caller in this step, so the bridge attribute must go.
+
 In `crates/aura-cli/src/main.rs` `dispatch_sweep`, replace the tail of the
 blueprint branch (:4471-4475):