fix: preserve locked snapshot visibility

(cherry picked from commit 3c3395b)

Author: ndycode

lib/storage/account-snapshot.ts

@@ -15,6 +15,13 @@ export async function statSnapshot(
 		return { exists: true, bytes: stats.size, mtimeMs: stats.mtimeMs };
 	} catch (error) {
 		const code = (error as NodeJS.ErrnoException).code;
+		if (code === "EBUSY" || code === "EPERM") {
+			deps.logWarn("Backup candidate is locked", {
+				path,
+				error: String(error),
+			});
+			return { exists: true };
+		}
 		if (code !== "ENOENT") {
 			deps.logWarn("Failed to stat backup candidate", {
 				path,

test/account-snapshot.test.ts

@@ -28,6 +28,22 @@ describe("statSnapshot", () => {
 			expect.objectContaining({ path: "locked.json" }),
 		);
 	});
+	it("treats locked snapshots as existing when stat returns EBUSY", async () => {
+		const logWarn = vi.fn();
+		await expect(
+			statSnapshot("locked.json", {
+				stat: vi.fn(async () => {
+					throw Object.assign(new Error("busy"), { code: "EBUSY" });
+				}),
+				logWarn,
+			}),
+		).resolves.toEqual({ exists: true });
+		expect(logWarn).toHaveBeenCalledWith(
+			"Backup candidate is locked",
+			expect.objectContaining({ path: "locked.json" }),
+		);
+	});
+
 });
 
 describe("describeAccountSnapshot", () => {