Keep the saved order of recent repositories; it was reversed on every start

src/lib/recents.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { addRecent, MAX_RECENTS } from "./recents";
+import { addRecent, MAX_RECENTS, mergeRecents } from "./recents";
 
 describe("addRecent", () => {
   it("puts the path first", () => {
@@ -16,3 +16,12 @@ describe("addRecent", () => {
     expect(out).not.toContain(`/r${MAX_RECENTS - 1}`);
   });
 });
+
+describe("mergeRecents", () => {
+  it("keeps the saved order", () => {
+    expect(mergeRecents([], ["/a", "/b", "/c"])).toEqual(["/a", "/b", "/c"]);
+  });
+  it("puts a path opened before the settings arrived first, once", () => {
+    expect(mergeRecents(["/b"], ["/a", "/b", "/c"])).toEqual(["/b", "/a", "/c"]);
+  });
+});