Done. Summary of the experiment:

**Two-Channel Universality Test** — tested whether the two-channel decomposition (TWO_CHANNEL_DECOMPOSITION) is unique to primes or generic for Z/6Z-structured sequences, using 3 synthetic models (MARKOV, CLASS_SHUFFLE, MAG_SHUFFLE) with 20 trials each.

**Results**:
- **Residue amplitude (-0.13)**: algebraic — Markov chain with same transition probs reproduces it exactly
- **Residue decay shape (alpha=1.24)**: number-theoretic — Markov gives 1.60, primes have long-range class memory beyond pairwise transitions (connects to prime race / Dirichlet L-function zeros)
- **Magnitude anti-correlation (-0.032)**: entirely number-theoretic — only real sequential ordering produces it
- **Same-class asymmetry (2.1x)**: **FALSIFIED as three-point correlation** — CLASS_SHUFFLE with random classes gives 2.6x. It's sub-sampling geometry, not class-specific number theory

The decomposition framework is generic; the content is half algebraic (residue amplitude), half number-theoretic (residue decay + magnitude channel). Files: `exp_two_channel_universality.py`, report in `agent_20260419_0755.md`, seme updated.