Z₉ Phenomenology: Neutrino Predictions, Flavor Safety, and Experimental Tests

The Z9 discrete flavor symmetry framework derives 32 Standard Model parameters and the gauge group from a single algebraic structure. This paper tests the framework's phenomenological viability and extracts predictions for current and next-generation experiments. We demonstrate three key results: (1) the type-I seesaw mechanism with Z9 charge assignments robustly produces normal neutrino mass ordering with m1 = 0; (2) the Z9 charge assignments provide natural flavor protection, with all FCNC processes safe; (3) renormalization group running of the weak mixing angle is consistent at the 2% level. Specific predictions for DUNE, Hyper-Kamiokande, KATRIN, MEG II, and Mu3e are tabulated.