feat(managed): add unified Tokio managed task

crates/irtt-client/src/managed/target_id.rs

@@ -0,0 +1,47 @@
+use std::{fmt, sync::Arc};
+
+/// Caller-owned stable target identity.
+#[derive(Clone, Eq, Hash, Ord, PartialEq, PartialOrd)]
+pub struct TargetId(Arc<str>);
+
+impl TargetId {
+    /// Construct a target identifier.
+    pub fn new(value: impl Into<Arc<str>>) -> Self {
+        Self(value.into())
+    }
+
+    /// Borrow the identifier as a string slice.
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+impl fmt::Debug for TargetId {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("TargetId").field(&self.0).finish()
+    }
+}
+
+impl fmt::Display for TargetId {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(&self.0)
+    }
+}
+
+impl From<&str> for TargetId {
+    fn from(value: &str) -> Self {
+        Self::new(value)
+    }
+}
+
+impl From<String> for TargetId {
+    fn from(value: String) -> Self {
+        Self::new(value)
+    }
+}
+
+impl AsRef<str> for TargetId {
+    fn as_ref(&self) -> &str {
+        self.as_str()
+    }
+}