Fix mbp10_data_dir/trades_data_dir TOML→DQNHyperparameters wiring gap.
Fields were deserialized but silently dropped — now applied in
training_profile.rs apply_to(). Production TOML activates OFI (8 features
from MBP-10 order book), smoketest leaves it off for fast iteration.
3 new OFI integration tests: state vector positioning, graceful
degradation (zero-fill without MBP-10), feature name ordering.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>