feat: add comprehensive end-to-end test suite

e2e/test_status_fifo_level.ts

@@ -0,0 +1,29 @@
+import { setupTest, startEngine, openCmdFifo, wait, ensureGenTone, execSync, readStatusNonBlock, teardownTest } from './test_utils';
+import * as globals from "./test_globals";
+
+export async function testStatusFifoLevelLine(): Promise<void> {
+  console.log("\nTest: STATUS FIFO LEVEL LINE AFTER TONE");
+  const engine = await startEngine();
+  openCmdFifo();
+  await wait(500);
+
+  // Play tone directly (not through TUI)
+  ensureGenTone();
+  execSync(`${globals.GEN_TONE_BIN} 1.0 "looper:ch0in"`, { timeout: 5000 });
+
+  // Wait for engine to write status
+  await wait(2000);
+
+  // Read status FIFO directly
+  const data = readStatusNonBlock();
+  const hasLevel = data.includes("LEVEL=");
+  console.log("  Status FIFO data:", data.slice(0, 500));
+  if (hasLevel) {
+    console.log("  PASS: LEVEL line found in status FIFO");
+  } else {
+    console.log("  FAIL: No LEVEL line in status FIFO. Check engine RMS computation.");
+    engine.kill(); teardownTest();
+    throw new Error("Level line missing from status FIFO");
+  }
+  engine.kill(); teardownTest();
+}