Task 5 added smoothness_base_lambda to PerceptionTrainerConfig but only
updated the struct definition + Default impl. Eight test sites in
perception_overfit.rs and one site in alpha_train.rs construct the
config via explicit field list (no ..Default::default() spread), so
they broke with E0063 missing-field errors under cargo check
--all-targets.
Per feedback_no_partial_refactor.md: when a contract changes, every
consumer migrates atomically. This commit adds smoothness_base_lambda:
0.0 to all 9 sites so the workspace compiles cleanly. The
alpha_train.rs value of 0.0 is a placeholder — Task 7 will replace it
with cli.smoothness_base_lambda once the CLI flag is added.
4a32186a5f