The baryon asymmetry problem — why the observable universe contains matter but essentially no antimatter — is one of the outstanding unsolved problems of cosmology. Standard approaches require baryon number violation, CP violation, and departure from thermal equilibrium (Sakharov 1967). We propose an alternative resolution grounded in the temporal structure of the cosmological singularity. In the Slow Big Bang framework, the singularity corresponds to a state of formally infinite causal propagation rate with no preferred temporal direction. As the propagation rate decreased from infinity, temporal symmetry broke spontaneously: the causal network acquired a definite propagation direction, bifurcating into a positive-time branch (our universe, matter) and a negative-time branch (antimatter). There is no asymmetry: equal quantities of matter and antimatter exist, separated by temporal direction. Pair annihilation is reinterpreted as a boundary event where the two branches momentarily reconnect. The CPT theorem is naturally preserved. No Sakharov conditions are required. This is Paper 3 in the Pixel Theory series. Companion papers: Paper 1: https://doi.org/10.5281/zenodo.20491684 Paper 2: https://doi.org/10.5281/zenodo.20529501 Paper 4: https://doi.org/10.5281/zenodo.20525925 Paper 5: https://doi.org/10.5281/zenodo.20531541 Paper 6: https://doi.org/10.5281/zenodo.20585009 Paper 7: https://doi.org/10.5281/zenodo.20540035 ```