V.D20 — Three Temporal Epochs

The refinement tower decomposes into three temporal epochs: the pre-temporal epoch (n < n_ign, no operationally meaningful time readout), the temporal epoch (n_ign <= n <= n_coh, proper-time readout operational), and the post-temporal epoch (n > n_coh, ticks shorter than any distinguishable interval, temporal readout saturates).