feat: auto-delete old conversations, and stop a tool call that repeats (#15)

src/__mocks__/@vicinae/api.ts

@@ -47,6 +47,27 @@ export function getPreferenceValues<T = Record<string, unknown>>(): T {
   return preferenceOverride as T;
 }
 
+/**
+ * Toast stubs.
+ *
+ * Recorded rather than discarded, so a test can assert that a sweep only speaks
+ * up when it actually deleted something.
+ */
+export const __toasts: { title: string; message?: string }[] = [];
+
+export const Toast = {
+  Style: { Success: "success", Failure: "failure", Animated: "animated" },
+};
+
+export async function showToast(options: { title: string; message?: string }): Promise<void> {
+  __toasts.push({ title: options.title, message: options.message });
+}
+
+/** Test-only helper: forgets the toasts shown so far. */
+export function __resetToasts(): void {
+  __toasts.length = 0;
+}
+
 /**
  * The runtime `environment`. Only `supportPath` is exercised, by the snip
  * directory, and a stable fake path keeps those assertions independent of where