Portal Unavoidability Requires One End-to-End Source Constructor
WP838 isolates the precise source principle required by the flavor objective.
One source-natural constructor must generate, from the primitive oriented
incidence, the representation and current, finite spectral action, interacting
beta system and selected basin, finite threshold map, and calibrated labelled
physical16 realization. Separately valid pieces do not acquire common-source
authority merely because their coordinates compose.
For the conditional WP821 coefficients (a=b=d=f=1,c=3), the primitive contrast (q_3-q_2=1) gives the exact positive prediction
with local infrared stability eigenvalues (1/2) and (2). The same incidence with (c=4) instead gives (x_*=1/3), proving that incidence alone does not make the magnitude unavoidable. An inclusive threshold map and an inclusive detector row each annihilate the contrast, independently. Aspect's comb reference supplies a common comparison frame but explicitly does not select the source flavor value.
The first missing arrow is from primitive incidence plus finite spectral data to a uniquely derived interacting action and beta coefficients. Source-action authority, global basin selection, threshold survival, and labelled calibrated readout remain separate required gates.
Verification: 12 of 12 exact checks pass in
research/flavor/checkers/wp838_single_constructor_portal_unavoidability_certificate.py.
Graph admission: ev-000000007879-376fe3a6-0469-4ff3-8dc1-3daa9ce6f941.