feat: add comprehensive end-to-end test suite

e2e/test_record_on_missing_channel.ts

@@ -0,0 +1,50 @@
+import { setupTest, startEngine, startClientInTmux, wait, tmuxSendKeys, tmuxCapturePane, teardownTest } from './test_utils';
+
+export async function testRecordOnMissingChannel(): Promise<void> {
+  console.log("\nTest: RECORD ON MISSING CHANNEL (col 2, row 2)");
+  setupTest();
+  const engine = await startEngine();
+  await startClientInTmux();
+  // Do NOT add any channels – only channel 0 exists
+  await wait(500);
+
+  // Navigate to row 2, col 2 (two rights, two downs)
+  tmuxSendKeys("looper", "0", "l");
+  tmuxSendKeys("looper", "0", "l");
+  await wait(200);
+  tmuxSendKeys("looper", "0", "j");
+  tmuxSendKeys("looper", "0", "j");
+  await wait(200);
+
+  // Verify selection line
+  let pane = tmuxCapturePane("looper", "0");
+  if (!pane.includes("Selected: Grid 0, Row 2, Col 2")) {
+    console.log("  FAIL: Could not navigate to Row 2, Col 2");
+    engine.kill(); teardownTest();
+    throw new Error("Navigation to (2,2) failed");
+  }
+
+  // Press 't' to start recording (no extra key – TUI polls itself)
+  tmuxSendKeys("looper", "0", "t");
+  await wait(1500);
+
+  // Check the grid shows 'R' near cell (2,2)
+  pane = tmuxCapturePane("looper", "0");
+  const paneLines = pane.split("\n");
+  let cellLine = -1, recordLine = -1;
+  for (let i = 0; i < paneLines.length; i++) {
+    if (paneLines[i].includes(" 2")) cellLine = i;
+    if (paneLines[i].includes("R"))  recordLine = i;
+  }
+  if (cellLine !== -1 && recordLine !== -1 && Math.abs(recordLine - cellLine) <= 2) {
+    console.log("  PASS: Grid shows 'R' indicator near cell 2");
+  } else {
+    console.log("  FAIL: Could not find 'R' near cell 2 in pane");
+    console.log("  Pane excerpt:\n" + pane.slice(0, 1000));
+    engine.kill(); teardownTest();
+    throw new Error("Grid indicator missing for col 2");
+  }
+
+  engine.kill();
+  teardownTest();
+}