feat(aura-engine,aura-cli): named param binding — single-run .with()/.bootstrap() (0030 iter 1)

Bind a blueprint's open knobs by name for a single run instead of by a positional,
Scalar-wrapped Vec in param_space() order:

    bp.with("sma_cross.fast", 2).with("sma_cross.slow", 4).with("scale", 0.5).bootstrap()

A pure authoring layer over the existing Composite::param_space / bootstrap_with_params
primitives; the engine run loop and the construction core are untouched (C1/C12/C19/C23
preserved). Raw literals lower via Into<Scalar> (the literal fixes the variant: 2->I64,
0.5->F64, pinned by e97906a); the match key is the exact param_space() name — path-qualified
for a composite-interior knob (sma_cross.fast), bare for a root-level knob (scale).

This iteration (single-run side):
- BindError vocabulary (name-qualified); the full enum incl. the sweep-only EmptyAxis is
  defined and re-exported now, so the unconstructed variant is reachable public API, not
  dead_code — EmptyAxis is constructed in iteration 2 (the sweep side).
- resolve(): the shared name-resolution core, a total error order — Phase 1 per binding in
  input order (a UnknownKnob / b AmbiguousKnob / d DuplicateBinding), Phase 2 slot walk in
  param_space() order (e MissingKnob / f KindMismatch); first failing check wins.
- Composite::with -> Binder -> Binder::bootstrap; .with() not .bind() (bind is reserved for
  #55's structural-constant overlay).
- The CLI sample single-run test converted to the named form (behaviour-preserving).

Verified (run by the orchestrator, not the agent's claim): 9 new aura-engine tests green —
resolve round-trip + one per single-run BindError variant + two precedence tests + the C1
named-equals-positional equivalence over the sample composite harness; the converted CLI
sample test green; full `cargo test --workspace` green and `cargo clippy --workspace
--all-targets -- -D warnings` clean.

Iteration 2 (the sweep side: axis / SweepBinder / resolve_axes / EmptyAxis + the sweep CLI
conversion) is next. refs #35

crates/aura-cli/src/main.rs

@@ -517,7 +517,10 @@ mod tests {
         // so a caller can bootstrap one point, run it, and drain both sinks.
         let (bp, rx_eq, rx_ex) = sample_blueprint_with_sinks();
         let mut h = bp
-            .bootstrap_with_params(vec![Scalar::I64(2), Scalar::I64(4), Scalar::F64(0.5)])
+            .with("sma_cross.fast", 2)
+            .with("sma_cross.slow", 4)
+            .with("scale", 0.5)
+            .bootstrap()
             .expect("sample blueprint compiles under a valid point");
         h.run(vec![synthetic_prices()]);
         assert!(!rx_eq.try_iter().collect::<Vec<_>>().is_empty(), "equity sink drained empty");