audit: cycle 0023 (#48) — drift reconciled; render paths unified

Architect drift review (bb90c42..481172a): no contract drift. C9 (render
reads structure + label()/params()/output() only, never eval), C8 (sink =
zero-output leaf, no special case), C12 (blueprint = root composite is
render-structural only; types stay distinct), C23 (consumer-prefix mirrors
the := binding), #38 (composites stay opaque) — all hold. Three fidelity
items, resolved:

- [high, fixed] spec acceptance over-claimed: the SimBroker slot-stub box read
  as in-scope though the work is deferred. Spec amended — the stub acceptance
  is annotated against #49, the met boxes checked.
- [medium, recorded] no docs/plans/0023: this cycle ran spike→refactor under
  user steering instead of planner→implement, because the edge-label-vs-
  consumer-side fork needed an empirical probe (ascii-dag silently drops edge
  labels on collision) before a placeholder-free plan was possible. A plan
  RECORD (not a task plan) now holds the 0023 slot so the counter pairing
  stays intact and the next cycle takes 0024.
- [low, carry-on] multi_output_field_name's leaf-producer fallback is latent
  and untested (no multi-output leaf in the corpus). Carried as debt.

Regression scripts: none configured (no-op). Build/test/clippy green.
Deferred stub work is tracked in #49 (user-signed).

closes #48

docs/plans/0023-unify-blueprint-render.md

@@ -0,0 +1,51 @@
+# Unify the Blueprint Main-Graph Render — Implementation Record
+
+> **Parent spec:** `docs/specs/0023-unify-blueprint-render.md`
+>
+> **This is NOT a task-by-task plan.** Cycle 0023 was implemented through an
+> exploratory spike→refactor path under direct user steering, not the standard
+> `planner → implement` decomposition. This file exists to keep the
+> spec/plan counter pairing intact (`naming.counter_dirs: [docs/specs, docs/plans]`)
+> and to record *why* the standard plan artefact is absent, so the next cycle
+> takes slot 0024 and a future reader does not mistake the gap for a lost file.
+
+**Goal:** one shared render path for the blueprint main graph and the composite
+`where:` interior — the blueprint is the root composite.
+
+## Why no task-by-task plan
+
+The spec named the direction but left one detail to "the planner/implementer call
+against ascii-dag's actual capability": *where* a multi-output producer's selected
+field surfaces. Resolving it needed an **empirical** answer, not a paper decision:
+
+1. The obvious default (an ascii-dag per-edge label) turned out to be unreliable —
+   ascii-dag 0.9.1's `can_place_label` silently drops a label it cannot place
+   without collision (verified by throwaway probe against the real macd topology).
+   The Plain path drops it with no legend; the colored path shifts it to a legend.
+2. So the field had to move to the **consumer node label**
+   (`[histogram → Exposure(scale)]`), which also removed the `render_flat`
+   signature change entirely (no edge-label slot).
+
+A placeholder-free plan could not be written before that probe, so the work ran as
+a spike (validate the notation visually with the user) → refactor (collapse the
+duplication into one shared `render_graph` over borrowed slices — `LeafFactory`
+is not `Clone`, so an owned root-composite adapter is impossible).
+
+## What shipped (commits)
+
+- `5dd9503` — spec: 0023 unify blueprint main-graph render
+- `481172a` — feat(aura-cli): unify blueprint main-graph render through one
+  shared core (`render_graph`; `ParamNames` {Aliases, Factory}; `Entry` unifying
+  `Role`/`SourceSpec`; deleted the duplicated `blueprint_leaf_label`)
+
+Production change confined to `crates/aura-cli/src/graph.rs`; goldens re-captured
+in `crates/aura-cli/src/main.rs`. No engine change. Build/test/clippy green.
+
+## Deferred / debt (filed, not lost)
+
+- **Issue #49** — top-level blueprint multi-input leaves render without `#`-slot
+  stubs (`stub_ctx: None`); `fan_in_identifiers`/`signature_of` stays
+  composite-coupled. User-signed deferral.
+- **Latent, untested** — `multi_output_field_name`'s leaf-producer fallback
+  (`from_field > 0` → index string) is unexercised (no multi-output leaf in the
+  current corpus); carried as latent code, no anchoring test this cycle.

docs/specs/0023-unify-blueprint-render.md

@@ -165,9 +165,12 @@ spec-owned):
     [Exposure(scale)]           ← factory-declared param name, value-empty
 ```
 
-`SimBroker`, with two wired input slots (exposure, price), gains slot stubs the
-same way the composite interior already shows them (e.g. `[SimBroker(#…,#…)]`);
-`Recorder` (no params, one input, a sink) is unchanged — a bare terminal leaf.
+`SimBroker`, with two wired input slots (exposure, price), would gain slot stubs
+the same way the composite interior already shows them (e.g. `[SimBroker(#…,#…)]`)
+— **deferred to issue #49**: as shipped, `SimBroker` renders bare, because
+`fan_in_identifiers`/`signature_of` is still composite-coupled and threading the
+blueprint case through it was carved out (user-signed). `Recorder` (no params,
+one input, a sink) is unchanged — a bare terminal leaf.
 The headline is legibility: the histogram selection and `Exposure`'s
 parameterisation are now on the page.
 
@@ -285,8 +288,8 @@ render has (the golden tests are byte-exact, layout is RNG-free).
 
 - **Golden re-capture, value-asserted (not just re-blessed).** `blueprint_view_golden`
   (`crates/aura-cli/src/main.rs:494`) is re-captured; the diff must show the new
-  information (a param name on `[Exposure …]`, slot stubs on `[SimBroker …]`),
-  proving enrichment rather than a blind re-bless.
+  information (a param name on `[Exposure …]`; the `[SimBroker …]` stubs are
+  deferred to #49), proving enrichment rather than a blind re-bless.
 - **The headline assertion (macd):** a test on `render_blueprint(&macd_blueprint())`
   asserts the macd→Exposure edge surfaces `histogram` and that `[Exposure(scale)]`
   shows its param — the legibility property the cycle exists to buy. Extends the
@@ -324,13 +327,17 @@ Against aura's feature-acceptance criterion (CLAUDE.md):
 
 Concretely, the cycle is done when:
 
-- [ ] `aura graph --macd`'s main graph shows the `histogram` field on the
-      macd→Exposure connection and `scale` on the `Exposure` leaf.
-- [ ] `SimBroker`'s two input slots render as stubs in the main graph (the same
-      enrichment the composite interior already shows).
-- [ ] Single-output producers carry no field label; the sma_cross sample golden
+- [x] `aura graph --macd`'s main graph shows the `histogram` field on the
+      macd→Exposure connection and `scale` on the `Exposure` leaf. (Shipped as a
+      consumer-side prefix `[histogram → Exposure(scale)]`, not an edge label —
+      ascii-dag drops edge labels on collision; see Architecture.)
+- [ ] **Deferred to #49.** `SimBroker`'s two input slots render as stubs in the
+      main graph (the same enrichment the composite interior already shows). As
+      shipped, `SimBroker` renders bare — the stub machinery stays
+      composite-coupled this cycle.
+- [x] Single-output producers carry no field label; the sma_cross sample golden
       shows no spurious labels.
-- [ ] The `where:` section's existing assertions still pass (unchanged in spirit).
-- [ ] Composites remain opaque in the main graph (#38 retained).
-- [ ] `cargo test --workspace` and clippy are green; goldens re-captured with
+- [x] The `where:` section's existing assertions still pass (unchanged in spirit).
+- [x] Composites remain opaque in the main graph (#38 retained).
+- [x] `cargo test --workspace` and clippy are green; goldens re-captured with
       visible new information.