01b5b95c

By: ValentinHirschi <valentin.hirschi@gmail.com>

graph: route dependent external momenta in hand-written numerators

A numerator that names the dependent external momentum P(i, ...) (the
one fixed by momentum conservation) left it unbound: routing rewrites
only edge momenta Q(e, ...), and only the independent P(i) are bound.
Write each dependent P(i, ...) as its edge momentum Q(e_i, ...) before
routing, so it goes through the same signature as the propagators.
Numerators without a dependent P are unchanged (nothing is registered).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>