Backpressure-driven Fairness

Co-Authored-By: brekotis <93345790+brekotis@users.noreply.github.com>

src/transport/middle_proxy/fairness/mod.rs

@@ -0,0 +1,13 @@
+//! Backpressure-driven fairness control for ME reader routing.
+//!
+//! This module keeps fairness decisions worker-local:
+//! each reader loop owns one scheduler instance and mutates it without locks.
+
+mod model;
+mod pressure;
+mod scheduler;
+
+pub(crate) use model::{
+    AdmissionDecision, DispatchAction, DispatchFeedback, PressureState, SchedulerDecision,
+};
+pub(crate) use scheduler::{WorkerFairnessConfig, WorkerFairnessSnapshot, WorkerFairnessState};