feat(backup): import a backup, swapped in on the next start

app/src/lib/fake.ts

@@ -4,6 +4,7 @@
 
 import type { BotloftApi } from "./api";
 import { FakeAllow } from "./fakeAllow";
+import { backupHandlers } from "./fakeBackup";
 import { botHandlers } from "./fakeBots";
 import { FakeBrowser } from "./fakeBrowser";
 import { FakeChat } from "./fakeChat";
@@ -282,6 +283,7 @@ export class FakeBotloft implements BotloftApi {
     ...this.reactions.handlers(),
     ...this.lesson.handlers(),
     ...usageHandlers(this),
+    ...backupHandlers(this),
     ...searchHandlers(this),
   };
 }

app/src/lib/fakeBackup.ts

@@ -0,0 +1,54 @@
+// The fake daemon's backups (spec 14.2): what an export would hold, from
+// the fake crews, at a made-up path, and a backup that opens only with
+// `FAKE_PASSPHRASE`. Nothing is sealed, written or restored.
+
+import type { FakeBotloft, Handlers } from "./fake";
+import { type BackupManifest, RpcErrorCode } from "./protocol.gen";
+import { RpcError } from "./rpc";
+
+type BackupMethods = Extract<keyof Handlers, `backup.${string}`>;
+
+/** The passphrase the fake's backups open with. */
+export const FAKE_PASSPHRASE = "correct horse";
+
+function refused(reason: string, message: string): RpcError {
+  return new RpcError(RpcErrorCode.validation, message, reason);
+}
+
+function manifestOf(fake: FakeBotloft): BackupManifest {
+  return {
+    format: 1,
+    createdAt: fake.now,
+    version: "0.10.0",
+    crews: [...fake.crews.values()].map((crew) => ({
+      name: crew.name,
+      bots: [...fake.bots.values()]
+        .filter((bot) => bot.crewId === crew.id && bot.archivedAt === null)
+        .map((bot) => bot.name),
+      workFolder: crew.workFolderChosen ? crew.workFolder : null,
+    })),
+  };
+}
+
+export function backupHandlers(fake: FakeBotloft): Pick<Handlers, BackupMethods> {
+  return {
+    "backup.export": ({ passphrase }) => {
+      if ([...passphrase].length < 8) {
+        throw refused("short_passphrase", "the passphrase must have at least 8 characters");
+      }
+      return {
+        path: "C:\\Users\\owner\\AppData\\Local\\Botloft\\exports\\botloft-2026-10-05-1430.botloft",
+        size: 1_234_567,
+        manifest: manifestOf(fake),
+      };
+    },
+    "backup.stage": ({ passphrase }) => {
+      if (passphrase !== FAKE_PASSPHRASE) {
+        throw refused("wrong_passphrase", "the passphrase is wrong, or the file is damaged");
+      }
+      return manifestOf(fake);
+    },
+    "backup.confirm": () => null,
+    "backup.cancel": () => null,
+  };
+}