Remove use_double_dqn, use_dueling, use_per, use_branching,
use_distributional, use_noisy_nets, use_huber_loss, and use_cql
from DQNConfig, DQNHyperparameters, and DqnParams structs.
These features are always enabled (Rainbow DQN standard). The boolean
flags were dead code — every constructor set them to true, and the
only code paths that set them to false were in tests that disabled
features for simplicity. With the fields removed, the features are
unconditionally active, eliminating ~490 lines of dead configuration.
Key changes:
- Struct field declarations removed from 3 core config structs
- Conditional branches (if use_X { ... } else { ... }) simplified:
dueling/branching/PER network creation is now unconditional
- Checkpoint metadata hardcodes "true" for backward compatibility
- Hyperopt search space index 11 (use_branching) fixed at 1.0
- TOML/YAML config files cleaned of removed fields
- Tests that toggled these flags updated or rewritten
45 files changed, -487 net lines. Zero new test failures.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Critical bug: all 3 DQN action selection methods (select_action,
select_action_with_confidence, select_action_inference) used
FactoredAction::from_index() which maps indices 0-4 to exposure_idx=0
(Short100) via division by 9. This is the root cause of action
diversity collapse during both training and production inference.
Fix: ExposureLevel::from_index() + OrderRouter::route_default() in all
DQN paths. Also fixes hyperopt objective thresholds (<10 → <3 for
5-action degenerate detection), stale defaults/comments, integration
test configs.
Files: dqn.rs (3 methods), trainer.rs (validation + select_action),
hyperopt/adapters/dqn.rs (thresholds), dqn_model.rs (comments),
train_baseline_rl.rs (default), reward.rs (comment),
dqn_integration.rs + ensemble_integration.rs (num_actions).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Move 17 library crates into crates/, CLI binary into bin/fxt,
consolidate 10 test crates into testing/, split config crate
from deployment config files.
Root directory reduced from 38+ to ~17 directories.
All Cargo.toml paths and build.rs proto refs updated.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
