fix: use system-reminder tags for conversation switch context (#933)

src/tests/cli/conversationSwitchAlert.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, test } from "bun:test";
+import { buildConversationSwitchAlert } from "../../cli/helpers/conversationSwitchAlert";
+import { SYSTEM_REMINDER_CLOSE, SYSTEM_REMINDER_OPEN } from "../../constants";
+
+describe("conversationSwitchAlert", () => {
+  test("wraps conversation switch context in system-reminder tags", () => {
+    const alert = buildConversationSwitchAlert({
+      origin: "resume-selector",
+      conversationId: "conv-123",
+      isDefault: false,
+      messageCount: 14,
+      summary: "Bugfix thread",
+    });
+
+    expect(alert).toContain(SYSTEM_REMINDER_OPEN);
+    expect(alert).toContain(SYSTEM_REMINDER_CLOSE);
+    expect(alert).not.toContain("<system-alert>");
+    expect(alert).not.toContain("</system-alert>");
+    expect(alert).toContain("Conversation resumed via /resume selector.");
+    expect(alert).toContain("Conversation: conv-123 (14 messages)");
+  });
+});