Stop losing tsnet state on redeploys

main.go

@@ -47,7 +47,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	dir, valid := os.LookupEnv("RUNTIME_DIRECTORY")
+	dir, valid := os.LookupEnv("STATE_DIRECTORY")
 	if !valid {
 		log.Fatal("RUNTIME_DIRECTORY must be set")
 	}