feat(cmd): add prx and prx-helper entrypoints

cmd/prx/main.go

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: MIT
+
+// Command prx is the unprivileged user-facing CLI.
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"prx/internal/cli"
+)
+
+func main() {
+	if err := cli.Execute(); err != nil {
+		fmt.Fprintln(os.Stderr, "prx: "+err.Error())
+		os.Exit(1)
+	}
+}