docs(aura-engine): drop two stale aura-cli cross-references in graph_model

kind_str and collect_distinct_composites no longer exist in aura-cli (it
consumes model_to_json directly), so the "mirrors aura-cli's ..." notes
pointed at nothing. Keep the substantive rationale (Debug is PascalCase).

crates/aura-engine/src/graph_model.rs

@@ -10,7 +10,7 @@ use crate::{BlueprintNode, Composite};
 use aura_core::{Firing, ScalarKind};
 
 /// A scalar kind as the lowercase type string the model + C4 colour palette use.
-/// Mirrors `aura-cli`'s `kind_str`; the `Debug` form is PascalCase, so explicit.
+/// The `Debug` form is PascalCase, so this lowercase mapping is spelled out.
 fn kind_str(k: ScalarKind) -> &'static str {
     match k {
         ScalarKind::I64 => "i64",
@@ -232,7 +232,7 @@ fn field_kind(c: &Composite, node: usize, field: usize) -> Option<ScalarKind> {
 }
 
 /// Every distinct composite type in the blueprint, first-seen order, keyed by
-/// name (mirrors aura-cli's `collect_distinct_composites`).
+/// name.
 fn distinct_composites(root: &Composite) -> Vec<&Composite> {
     fn walk<'a>(items: &'a [BlueprintNode], seen: &mut Vec<&'a str>, out: &mut Vec<&'a Composite>) {
         for it in items {