fix(fuse): wake the drain when a folder is made (B160)

Queueing a folder's create left the workers asleep until their 30 s idle
poll; every other enqueue woke them. A file's create still waits for the
release that attaches its bytes.

crates/pdfs-fuse/src/lib.rs

@@ -3688,6 +3688,12 @@ impl Core {
             Errno::EIO
         })?;
         debug!(%uid, %parent_uid, name, is_dir, "created node offline; queued");
+        // A folder is due now; without this the workers slept through it to
+        // the idle poll (B160). A file is not: its bytes ride on the create, and
+        // the release that attaches them wakes the drain.
+        if is_dir {
+            self.wake_drain();
+        }
         Ok(node)
     }
 

crates/pdfs-fuse/src/sim/daemon.rs

@@ -358,6 +358,30 @@ mod tests {
         let _ = std::fs::remove_dir_all(&dir);
     }
 
+    #[test]
+    #[ignore = "mounts FUSE: run with `cargo test -p pdfs-fuse sim:: -- --ignored`"]
+    fn a_folder_made_while_the_drain_is_idle_reaches_drive_at_once() {
+        // A new folder queued its create without waking the drain, so it sat
+        // until the workers' 30 s idle poll (B160).
+        let drive = FakeDrive::new();
+        let dir = scratch("idle-mkdir");
+        let daemon = Daemon::start(&dir, drive.client(1, Faults::lan())).unwrap();
+        assert!(wait_until(Duration::from_secs(30), || {
+            daemon.pending().is_ok_and(|items| items.is_empty())
+        }));
+
+        std::fs::create_dir(daemon.mountpoint.join("x")).unwrap();
+        assert!(
+            wait_until(Duration::from_secs(10), || drive.lookup("x").is_some()),
+            "{:?} {:?}",
+            daemon.pending(),
+            drive.tree()
+        );
+
+        assert!(matches!(daemon.stop(), Ok(MountOutcome::Shutdown)));
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
     #[test]
     #[ignore = "mounts FUSE: run with `cargo test -p pdfs-fuse sim:: -- --ignored`"]
     fn a_file_whose_upload_was_not_read_back_takes_two_writes_at_once() {