Switching to Rust for the CLI

cli/envsync-cli/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "envsync-cli"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+clap = { version = "4.5.60", features = ["derive"] }
+tokio = { version = "1.49.0", features = ["full"] }