feat: strengthen task workflow and compaction recovery

tests/ui.test.ts

@@ -170,6 +170,17 @@ test("tool errors show one summary line until expanded", () => {
   assert.deepEqual(expanded, ["✗ Update failed · 2 validation errors", "  - first", "  - second"]);
 });
 
+test("expanded task details tolerate an omitted description", () => {
+  const state = new TaskState();
+  state.add([{ name: "Name only" }]);
+  const result = {
+    content: [{ type: "text", text: "details" }],
+    details: { action: "get" as const, snapshot: state.snapshot(), affected: state.list() },
+  };
+  const lines = renderToolResult(result, true, plainTheme as never).render(80).map(stripAnsi);
+  assert.deepEqual(lines, ["✓ 1 task", "  ○ 1. Name only", "    Parent root · Children none"]);
+});
+
 test("snapshot stats count every task node", () => {
   assert.deepEqual(snapshotStats(fixture().list()), {
     total: 5,