refactor: extract is_aborted helpers, DRY 16 call sites

crates/zesdex-backend/src/app/util/abort.rs

@@ -0,0 +1,26 @@
+//! Shared abort-flag checks.
+//!
+//! The two variants (Option<Arc<AtomicBool>> and bare AtomicBool) are
+//! used across the agent runtime, subagent, workflow engine, and provider.
+
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
+
+/// Check whether an optional abort flag has been signalled.
+pub fn is_aborted(flag: &Option<Arc<AtomicBool>>) -> bool {
+    flag.as_ref().is_some_and(|f| f.load(Ordering::SeqCst))
+}
+
+/// Check whether a bare abort flag has been signalled.
+pub fn is_aborted_direct(flag: &AtomicBool) -> bool {
+    flag.load(Ordering::SeqCst)
+}
+
+/// Check whether an optional borrowed abort flag has been signalled.
+///
+/// This variant handles the `Option<&AtomicBool>` pattern used in
+/// service/provider.rs where the flag is passed as a by-value optional
+/// reference rather than an `Arc`.
+pub fn is_aborted_ref(flag: Option<&AtomicBool>) -> bool {
+    flag.is_some_and(|f| f.load(Ordering::SeqCst))
+}