test: strengthen durable behavior coverage after review

crates/irtt-client/Cargo.toml

@@ -25,6 +25,9 @@ default = []
 ancillary = ["dep:nix"]
 tokio = ["dep:tokio"]
 
+[dev-dependencies]
+irtt-server.workspace = true
+
 [package.metadata.docs.rs]
 all-features = true
 cargo-args = ["-Zunstable-options", "-Zrustdoc-scrape-examples"]