feat(tri): hybrid v2 Rust + golden checkpoints (N=5,10,15,20,50,152) #296

Context

tri math compare --hybrid (#277) implements hybrid v1: L1-normalized φ^k dotted with max-normalized Pell weights P_1..P_5, k=0..4. Reproducible CLI value ≈ 0.563780474444 (not L2 cosine).

Exploratory calculations (external / not in-tree) suggest an L2 cosine + growing N map may plateau near cos θ ≈ 0.9617 (θ ≈ 15.9°). That result is not Trinity SSOT until implemented, documented, and tested.

Goal

1. Freeze v1 vs v2 definitions in research/trinity-pellis-paper/hybrid-conjecture.md.
2. Extend tri math compare (flags or subcommand) for hybrid v2 and optional θ = arccos(clip(cosine similarity)) in Rust only.
3. Golden tests at checkpoints N = 5, 10, 15, 20, 50, 152 once the map is fixed (no chart-only claims).
4. Experience JSONL: log hybrid_v1, hybrid_v2, theta_deg, N, pellis_spec_seal_hash.

Non-goals

• Claiming Conjecture H1 "confirmed" from non-reproducible plots.
• Python on the verification critical path.

Acceptance

• cargo build --release + t27c suite green.
• One-line repro for collaborators that matches committed math.

Refs: #277, research/trinity-pellis-paper/hybrid-conjecture.md, bootstrap/src/math_compare.rs