feat: add scoped workdir delegation sessions

crates/workdir/src/local.rs

@@ -29,8 +29,8 @@ use crate::{
     CommandHandle, CommandOutput, CommandOutputRequest, CommandRequest, CommandStatus, EditRequest,
     EditResult, GlobRequest, GlobResult, GrepRequest, GrepResult, ListRequest, ListResult,
     ReadRequest, ReadResult, StatRequest, StatResult, Workdir, WorkdirError, WorkdirPath,
-    WorkdirSession, WorkdirSessionCapabilities, WorkdirSessionCapability, WriteRequest,
-    WriteResult,
+    WorkdirSession, WorkdirSessionCapabilities, WorkdirSessionCapability, WorkdirSessionHandle,
+    WriteRequest, WriteResult,
 };
 #[cfg(test)]
 use crate::{EntryKind, WriteOutcome};
@@ -371,6 +371,10 @@ impl WorkdirSession for LocalWorkdirSession {
         self.inner.capabilities
     }
 
+    async fn capture_delegation_source(&self) -> Result<WorkdirSessionHandle, WorkdirError> {
+        Ok(Arc::new(self.clone()))
+    }
+
     async fn stat(&self, request: StatRequest) -> Result<StatResult, WorkdirError> {
         self.ensure_capability(WorkdirSessionCapability::Read)?;
         let logical = request.path.clone();