fix: default features for cargo build/test, build each binary separately in release

- Set default = ["server", "pusher"] so cargo build/test works without flags
- Add required-features to each [[bin]] section
- make_release.sh builds each binary with --no-default-features for optimal size

Cargo.toml

@@ -5,7 +5,7 @@ edition = "2024"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 [features]
-default = ["server"]
+default = ["server", "pusher"]
 server = ["dep:actix-web", "dep:actix-governor", "dep:actix-rt", "dep:chrono", "dep:hex-conservative"]
 pusher = ["dep:zmq", "dep:reqwest", "dep:byteorder", "dep:base64", "dep:ed25519-dalek"]
 
@@ -50,7 +50,9 @@ panic = "abort"
 [[bin]]
 name = "bal-server"
 path = "src/bin/bal-server.rs"
+required-features = ["server"]
 
 [[bin]]
 name = "bal-pusher"
 path = "src/bin/bal-pusher.rs"
+required-features = ["pusher"]