audit: #319 cycle close — architect drift resolved, bench green

Architect review over 9cfe296..dc5f174 (drift_found -> all five items
fixed in this close): C24's family-machinery sentence re-amended to
current truth (synthetic walks are reproduce-only inputs since the
builder retirement; superseded text to the sidecar); the ported
generalize test's doc no longer promises the retired CrossInstrument
family handle and its stale section header is gone;
FamilyKind::CrossInstrument carries its C18 dead-machinery/read-back
note in code; live comments in campaign_run, bench surfaces, and
graph_construct name exec instead of the retired verbs; the five
inlined topology_hash copies in the bin test module consolidated into
one test helper. What holds, per the architect: C24<->code gated-intake
lockstep exact, C12's single-hash claim true in code, exec dispatch
matches C14's amended text.

Bench (regression gate) exit 0, all five fingerprints OK:
engine_throughput bars_per_s 14014049 (+0.1%), ingest_throughput
12935441 (-0.5%), campaign_sweep wall 1.407s (+0.9%), campaign_heavy
wall 5.688s (+2.1%), cli_fixed_cost run_ms 3.6 (+6.6%, spawn-floor
jitter under parallel-agent load, report-only). No baseline moved.
Also rides: the reviewer re-check's two comment nits (classify-once
wording, SIGPIPE example verb).

refs #319

crates/aura-cli/src/graph_construct.rs

@@ -726,7 +726,7 @@ pub fn introspect_cmd(cmd: crate::GraphIntrospectCmd, env: &aura_runner::project
 /// Phrase a blueprint-document `LoadError` as prose (Debug-leak-free; the
 /// engine error types are `Display`-free by convention — this is the CLI's
 /// presentation layer, like `format_op_error`). `pub(crate)`: shared by the
-/// `graph build` path (below) and `aura run`'s loaded-blueprint branch
+/// `graph build` path (below) and `aura exec`'s blueprint leg
 /// (main.rs) — env-agnostic on purpose, so both callers get identical wording
 /// (#184).
 pub(crate) fn blueprint_load_prose(e: &LoadError) -> String {
@@ -902,7 +902,7 @@ pub(crate) fn gate_authored_root_name(name: &str) -> Result<(), String> {
 /// Resolve a blueprint document's bytes from a file path or a 64-hex content
 /// id in the project store (the campaign-run target-addressing convention).
 /// The id shape is `aura_runner::axes::is_content_id` — the same predicate
-/// `campaign run`'s target resolution uses, so the two FILE-or-id surfaces
+/// `exec`'s campaign-target resolution uses, so the two FILE-or-id surfaces
 /// cannot drift apart on what counts as a store address. The `bool` names
 /// which branch fired: `true` for a FRESH FILE read, `false` for a STORE
 /// (content-id) fetch — `params_lines` (#331 delta re-review) uses it to