build(cli): add irtt-stats dependency and feature flag

crates/irtt-cli/Cargo.toml

@@ -5,7 +5,12 @@ edition.workspace = true
 license.workspace = true
 rust-version.workspace = true
 
+[features]
+default = ["stats"]
+stats = ["dep:irtt-stats"]
+
 [dependencies]
 clap = { version = "4.5", features = ["derive"] }
 irtt-client = { path = "../irtt-client" }
 irtt-proto = { path = "../irtt-proto" }
+irtt-stats = { path = "../irtt-stats", optional = true }