feat(schedule): add Schedule trait and EpsilonOrMax impl

EpsilonOrMax mirrors today's Game::likelihoods loop: sweep forward
then backward over iterating factors, capped at 10 iterations or
step <= 1e-6. Setup factors (TeamSum) run exactly once before the
loop begins.

ScheduleReport is the only public surface from this module.

src/lib.rs

@@ -20,6 +20,7 @@ mod history;
 mod matrix;
 mod message;
 pub mod player;
+pub(crate) mod schedule;
 pub mod storage;
 
 pub use drift::{ConstantDrift, Drift};
@@ -30,6 +31,7 @@ pub use history::History;
 use matrix::Matrix;
 use message::DiffMessage;
 pub use player::Player;
+pub use schedule::ScheduleReport;
 
 pub const BETA: f64 = 1.0;
 pub const MU: f64 = 0.0;