fix: fallback to in-memory state when convex functions are unavailable

test/state-store.test.js

@@ -5,7 +5,7 @@ const assert = require("node:assert/strict");
 const os = require("node:os");
 const path = require("node:path");
 const fs = require("node:fs/promises");
-const { JsonFileStateStore } = require("../src/lib/state-store");
+const { JsonFileStateStore, InMemoryStateStore } = require("../src/lib/state-store");
 
 test("load returns null when state file does not exist", async () => {
   const tempDir = await fs.mkdtemp(path.join(os.tmpdir(), "xartaudio-state-test-"));
@@ -33,3 +33,12 @@ test("save and load roundtrip state", async () => {
 
   assert.deepEqual(actual, expected);
 });
+
+test("in memory state store roundtrips without filesystem", async () => {
+  const store = new InMemoryStateStore();
+  assert.equal(await store.load(), null);
+
+  await store.save({ engine: { jobs: {} } });
+  const loaded = await store.load();
+  assert.deepEqual(loaded, { engine: { jobs: {} } });
+});