fix: improve parameter handling in listInstances for query parameters

src/api/machines.ts

···
   Effect.runPromise(
     pipe(
       parseQueryParams(c),
-      Effect.flatMap((params) => listInstances(!!params.all)),
+      Effect.flatMap((params) =>
+        listInstances(
+          params.all === "true" || params.all === "1",
+        )
+      ),
       presentation(c),
     ),
   ));