50105c1957
Adopt the name-based GraphBuilder (cycle 0039) in the CLI sample blueprints, which previously hand-wired raw positional Edge/Role/OutField via Composite::new. sma_cross, macd, signals, sample_blueprint_with_sinks, and macd_strategy_blueprint now read as typed-handle authoring: nodes are added for NodeHandles, ports/fields are wired by name (series/lhs/rhs/value, exposure/price, term[i], col[0], the macd histogram/signal/macd outputs), and build() lowers to the same index-wired Composite. This is what #64 was for — the builder was previously exercised only in its own tests; the showcase sample now dogfoods it. Behaviour-preserving: node order, instance names (.named), bound params (blend.weights[2]), and wiring are byte-identical, so param_space, the graph render, the single run, and the sweep are unchanged — guarded green by the existing aura-cli sample/sweep/param_space/render tests and the engine suite (full workspace 0 failed; clippy --all-targets -D warnings clean). sample_harness is deliberately left as a direct FlatGraph construction (baked Sma::new(2) nodes, the single-run path) — it builds the compilat directly, not a value-empty Composite, so it is not a GraphBuilder target.