[huashengshao]

Prepared native tree amplitudes currently freeze every model parameter. This adds ordered runtime parameter inputs to the existing exact coefficient program, allowing running couplings and model coefficients to change per lane without regenerating diagrams or rescaling a completed norm.

TreeProgram::prepare_with_runtime_parameters retains each declared parameter as a free input through FeynKit's existing scalar resolver, including analytic dependencies such as G=2*sqrt(pi*aS). The same native evaluator accepts real, positive-real or complex parameter batches for helicity coefficients, external component probes and spin-summed norms. Existing constructors retain their behavior. Runtime values preserve the selected carrier and working precision, and row identity, domains, immutable structural zeros and pole admission remain checked.

Exact graph coupling-order selection also rejects mixed-order vertex entries, whose componentwise-maximum label cannot implement a termwise projection. Unfiltered mixed vertices retain their full coherent sum.

Validation: all 81 native unit tests pass on both the standalone 9cdc dependency family and the coherent ROULETTE e93 consumer family with PATH=/nonexistent. Seven new checks include changing aS below binary64 resolution at 173 working bits, complete complex parameter phases, zero cached coupling defaults, runtime domains and row ordering, and explicit mixed-order rejection. The preparation/runtime source received independent review.

A separate consumer adapter test exposed roundoff in the pre-existing complex norm sum at a boosted gluon point. That adapter correctly rejects the residual imaginary part under its Unknown accuracy contract; exact Hermitian norm lowering is tracked in a separate follow-up and is not claimed by this parameter-input change.

Stacked on codex/native-qcd-amplitudes at a547843. No dependency revision changes, Python preparation, process source generation, or additional amplitude engine.