feat: justfile (#9)

Author: garrettladley

justfile

@@ -0,0 +1,27 @@
+# list available recipes
+default:
+    @just --list
+
+# fmt → lint → test → build
+[group("ci")]
+check: fmt lint test build
+
+# format with nightly (required for rustfmt.toml options)
+[group("dev")]
+fmt:
+    cargo +nightly fmt
+
+# run clippy with all workspace lints as errors
+[group("dev")]
+lint:
+    cargo clippy --all-targets --all-features -- -D warnings
+
+# run tests, accepts extra args: just test --lib
+[group("dev")]
+test *ARGS:
+    cargo test {{ARGS}}
+
+# compile the workspace
+[group("dev")]
+build:
+    cargo build