Symmetry and Charge Extensions of the Neutrino Standing-Carrier Space

Neutrino carrier ARC and HNL prediction 13/18 This paper applies the PCR target-extension calculus to the symmetry, charge, conjugation, and protection structures of the neutrino standing-carrier space. The preceding PCR papers establish the oscillation standing-carrier quotient, source-first carrier universe, simultaneous survivor residue, compatible role occupancy, direct kinematic-mass extension, lepton-number-violating extension, heavy-state and active-closure extension, and cosmological population and transport extension. PCR‑5D5 adds the symmetry and charge target while preserving the established oscillation base. The analysis treats symmetry and charge data as target-relative physical structures rather than as decorative labels. The extension includes charge assignments, integral charge-lattice coordinates, lepton-number and \(B-L\) data, conjugation relations, representation and anomaly constraints, vacuum compatibility, matching conditions, symmetry-protection information, and the source-to-target relations required for one coherent physical realization. A central objective is to distinguish genuinely standing symmetry and charge information from basis conventions, presentation choices, and unactivated formal possibilities. Charge and conjugation coordinates are retained only when they affect the declared target, its physical matching, its anomaly or vacuum consistency, its source realization, or its lawful continuation structure. The paper constructs source-faithful symmetry and charge realizations over the inherited standing-carrier space. These include explicit gauge-singlet right-handed-neutrino branches and a constructive vectorlike-singlet extension capable of realizing an exact-Dirac three-neutrino sector while preserving the required source, charge, gauge, anomaly, and oscillation-transparency conditions. The extended source is attached to the retained carrier rather than substituted for it. The resulting target extension preserves the established oscillation trace while exposing new symmetry- and charge-sensitive coordinates. It distinguishes exact symmetry-protected structure from symmetry-breaking deformations, charge-lattice representation from physical charge identity, and a constructive branch witness from a unique microscopic selection theorem. The analysis also establishes the appropriate failure and update boundaries. A charge, conjugation, or symmetry response that is undefined, out of scope, incompatible with the declared anomaly or vacuum structure, or unsupported by a shared physical witness is not silently promoted or discarded. It receives a typed failure, out-of-scope, or target-update disposition. The conclusion is deliberately bounded. The paper establishes the declared symmetry-and-charge extension and its source-faithful realization branches relative to the fixed PCR base, target, source ontology, and comparison class. It does not by itself select a unique neutrino carrier, force a unique Dirac or Majorana interpretation, establish a universal \(B-L\) law, determine a unique ultraviolet completion, or close every possible generalized-symmetry extension.