feat(sp15-p2a.1): LobBar canonical ABI + 4 synthetic market generators

Phase 2A scaffolding lands FIRST per spec §4.4 ABI contract. Phase 1.2
cost kernel reads LobBar; both dev synthetic and prod fxcache produce
LobBar — dev/prod parity per Q3.

Generators: flat_market, drift_market, ou_market, regime_switch_market
(seeded RNG for reproducible tests). Regime-switch test uses sticky
0.99/0.01 transitions (true regime persistence; spec's 50/50 was a
random walk, not a regime switch — corrected with code comment).

behavioral_suite test target wired into Cargo.toml; will run all
22 Phase 2 tests once they land in Phase 2B/2C.

Audit doc: SP15 Phase 2A.1 entry appended to docs/dqn-wire-up-audit.md
per Invariant 7 (component changes require audit-doc update).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/ml/Cargo.toml

@@ -272,6 +272,10 @@ path = "examples/hyperopt_baseline_rl.rs"
 name = "hyperopt_baseline_supervised"
 path = "examples/hyperopt_baseline_supervised.rs"
 
+[[test]]
+name = "behavioral_suite"
+path = "tests/behavioral/main.rs"
+
 [[bench]]
 name = "microstructure_bench"
 harness = false