refactor: converge storage io hot paths (#3029)

* refactor(issue-633): clarify layered io control policies

* refactor(issue-633): consolidate timeout and deadlock layers

* refactor(issue-633): align storage backpressure metadata

* refactor(issue-633): unify storage backpressure transitions

* refactor(issue-633): simplify watermark transition API

* test(issue-633): add storage backpressure transition test

* refactor(issue-633): align storage pipe meta shape

* refactor(issue-633): enrich storage monitor metadata

* refactor(issue-633): finalize storage backpressure convergence

* refactor(issue-633): complete scheduler layer convergence

* refactor(issue-633): reduce concurrency facade config duplication

* refactor(issue-633): migrate storage callsites to final policy names

* chore(issue-633): apply final pre-commit normalization

* refactor(issue-633): unify timeout wrapper dynamic size path

* refactor(issue-633): make concurrency policies copyable

* refactor(issue-633): converge storage io hot paths

* fix(issue-633): honor storage timeout min bound

* fix(storage): avoid timeout calc panic on huge sizes

* refactor(storage): consolidate timeout checks and test attrs

* fix(storage): harden io scheduler core config mapping

* refactor(storage): eliminate patch-on-patch patterns and dead code

- Remove trivial accessor methods on ConcurrencyConfig that just return pub fields
- Remove dead BackpressureEvent/BackpressureEventType types from concurrency crate
- Fix io_schedule test using wrong constructor (from_core_config -> from_scheduler_config)
- Update manager.rs to use config fields directly instead of removed accessors

* fix: adopt review feedback for config guards

* test: remove needless struct update defaults

* fix: harden timeout policy and preserve api alias

crates/concurrency/src/lib.rs

@@ -128,19 +128,19 @@ pub mod workers;
 
 // Public module exports with feature gates
 #[cfg(feature = "timeout")]
-pub use timeout::{TimeoutConfig, TimeoutGuard, TimeoutManager};
+pub use timeout::{TimeoutGuard, TimeoutManager, TimeoutManagerPolicy};
 
 #[cfg(feature = "lock")]
 pub use lock::{LockConfig, LockManager, LockScopeGuard, OptimizedLockGuard};
 
 #[cfg(feature = "deadlock")]
-pub use deadlock::{DeadlockConfig, DeadlockManager, RequestTracker};
+pub use deadlock::{DeadlockManager, DeadlockMonitorPolicy, RequestTracker};
 
 #[cfg(feature = "backpressure")]
-pub use backpressure::{BackpressureConfig, BackpressureManager, BackpressurePipe};
+pub use backpressure::{BackpressureManager, BackpressurePipe, PipeBackpressurePolicy};
 
 #[cfg(feature = "scheduler")]
-pub use scheduler::{IoStrategy, SchedulerConfig, SchedulerManager};
+pub use scheduler::{IoStrategy, SchedulerManager, SchedulerPolicy};
 
 // Configuration
 mod config;
@@ -155,19 +155,19 @@ pub mod prelude {
     //! Prelude module for convenient imports
 
     #[cfg(feature = "timeout")]
-    pub use crate::timeout::{TimeoutConfig, TimeoutGuard, TimeoutManager};
+    pub use crate::timeout::{TimeoutGuard, TimeoutManager, TimeoutManagerPolicy};
 
     #[cfg(feature = "lock")]
     pub use crate::lock::{LockConfig, LockManager, LockScopeGuard, OptimizedLockGuard};
 
     #[cfg(feature = "deadlock")]
-    pub use crate::deadlock::{DeadlockConfig, DeadlockManager, RequestTracker};
+    pub use crate::deadlock::{DeadlockManager, DeadlockMonitorPolicy, RequestTracker};
 
     #[cfg(feature = "backpressure")]
-    pub use crate::backpressure::{BackpressureConfig, BackpressureManager, BackpressurePipe};
+    pub use crate::backpressure::{BackpressureManager, BackpressurePipe, PipeBackpressurePolicy};
 
     #[cfg(feature = "scheduler")]
-    pub use crate::scheduler::{IoStrategy, SchedulerConfig, SchedulerManager};
+    pub use crate::scheduler::{IoStrategy, SchedulerManager, SchedulerPolicy};
 
     pub use crate::{ConcurrencyConfig, ConcurrencyFeatures, ConcurrencyManager};
 }