refactor(cli): reorganize project structure into modular commands

crates/irtt-cli/src/cmd/client/mod.rs

@@ -0,0 +1,12 @@
+pub mod args;
+pub mod output;
+pub mod run;
+#[cfg(feature = "stats")]
+pub mod summary;
+
+pub use args::{ClientArgs, OutputMode};
+pub use output::{
+    format_event, format_human_event, format_human_event_with_options, HumanEventStats,
+    HumanIpdvPair, HumanOutputOptions,
+};
+pub use run::run_stream;

crates/irtt-cli/src/cmd/mod.rs

@@ -0,0 +1,3 @@
+pub mod client;
+#[cfg(feature = "tui")]
+pub mod tui;