# 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.
