Rewrite init script in rust and fix non-shell CMDs

Cargo.toml

@@ -1,3 +1,11 @@
+[workspace]
+members = [".", "init"]
+
+[profile.release]
+opt-level = "z"
+lto = true
+strip = true
+
 [package]
 name = "slim"
 version = "0.1.0"
@@ -5,7 +13,7 @@ edition = "2024"
 
 [dependencies]
 anyhow = "1.0.104"
-base64 = "0.22"
+base64 = "0.23"
 clap = { version = "4.6.6", features = ["derive"] }
 flate2 = "1.1.9"
 serde = { version = "1.0.229", features = ["derive"] }