Consecutive Rankin-Cohen Bases, Full-Spark Periods, and Divisor-Tau Congruences

For $r\ge1$, let $K=2r+14$ and $d=\dim S_K$. We prove strict positivity for determinants of Mellin period functionals, yielding a full-spark theorem for periods in a fundamental half-range and, in particular, the mixed odd--even period independence conjecture of Xue. As a consequence, the consecutiv