The Quantum Capstone: Directed Emergence, Access Localization, and the Geometric Born Measure in Six-Throat Directed Geometry

Paper XXI completes the microscopic extension of Six-Throat Directed Geometry by introducing a directed spinor dynamics on the regular six-throat spacetime and carrying that dynamics through the exact periodic closure. The construction separates persistent physical identity, directed state, and observer access, so a state may pass through a direction-neutral condition without annihilation while observational localization remains an access restriction rather than a second global evolution law. The microscopic dynamics is formulated with a curved-space Dirac equation containing a directed scalar mass law. At directional zero, the effective mass returns smoothly to its reference value and the spinor evolution remains regular. The associated Dirac current is positive and conserved, providing an invariant microscopic measure through directed reversal. The closed geometry is equipped with an antiperiodic spin structure over the 15.6-length geometric cycle, while bilinear observables remain periodic after one complete spatial circuit. The global construction yields a regular zero passage, a resolved directed spectral splitting, dynamical conservation of the spinor norm, channel-resolved decoherence, and a geometric detector measure. Observer localization is represented by projection onto the observer-accessible subspace while the global physical state remains intact. For flux-orthogonal detector channels, the conserved current partitions according to the squared channel amplitudes. The resulting normalized detector measure reproduces the standard Born weights as a current-flux theorem rather than as a primitive probability postulate. An explicit six-channel detector-surface calculation gives a maximum Born-weight residual of approximately 1.43 × 10^-14, while the integrated cross-channel surface flux remains below approximately 2.22 × 10^-16. The accompanying reproducibility package includes the global kinetic spectrum, parametric mass spectrum, directed spectral splitting, zero-passage dynamics, dynamic channel flux, detector-surface flux, final consistency audit, and the inherited geometric generators required by the calculation chain. The complete numerical outputs are distributed with the package. The result is a microscopic closure in which existence, direction, zero passage, geometric emergence, coherence, decoherence, observer access, and detector statistics are represented within one regular geometric framework.