Merge origin/main into macos

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

lib/runtime/src/platform/linux_x86_64/driver.rs

@@ -1,4 +1,6 @@
-//! Public runtime driver primitives.
+//! RUIN Runtime Driver for Linux x86_64.
+//!
+//!
 
 use std::cell::Cell;
 use std::cell::RefCell;
@@ -88,12 +90,21 @@ pub struct ReadyEvents {
 
 /// Low-level Linux runtime driver backed by `io_uring`.
 pub struct Driver {
+    /// The `io_uring` instance driving this runtime thread.
     ring: IoUring,
+    /// Shared notifier that other threads can use to wake this runtime thread.
     notifier: Arc<NotifierInner>,
+    /// Next sequence number for generated completion tokens.
     next_token: Cell<u64>,
+    /// The token of the currently active timer, if any timer is armed.
     active_timer_token: Cell<Option<u64>>,
+    /// Accumulated count of pending wake notifications that have not yet been triggered.
     pending_wakes: Cell<u64>,
+    /// Accumulated count of pending timer expirations that have not yet been triggered.
     pending_timers: Cell<u64>,
+    /// Map of active completion tokens to associated handlers. When a CQE is received with a token in this map, the
+    /// corresponding handler will be invoked with the CQE and removed from the map. This is the core mechanism by which
+    /// async operations are tracked and dispatched to their continuations.
     completions: RefCell<HashMap<u64, CompletionHandler>>,
 }