feat(s3-storage): add backup metadata, upload verification, restore, and retention

tests/backend/s3-storage-retention.test.ts

@@ -0,0 +1,72 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { getExpiredObjectKeys } from "../../src/server/services/s3-storage-retention.service";
+
+const now = Date.parse("2026-07-15T00:00:00.000Z");
+
+function destination(overrides: Record<string, unknown> = {}) {
+  return {
+    id: "destination-1",
+    userId: "user-1",
+    organizationId: "org-1",
+    name: "Backups",
+    bucket: "bucket",
+    endpoint: null,
+    region: "ap-southeast-1",
+    accessKeyId: "access-key",
+    secretAccessKeyEnc: "encrypted",
+    additionalFlags: [],
+    retentionDays: null,
+    maxBackupCount: null,
+    objectPrefix: "doktainer/backups",
+    ...overrides,
+  };
+}
+
+test("retention removes objects older than the configured number of days", () => {
+  const keys = getExpiredObjectKeys(
+    [
+      {
+        key: "old.tar.gz",
+        lastModified: new Date("2026-07-01T00:00:00.000Z"),
+        size: 10,
+      },
+      {
+        key: "recent.tar.gz",
+        lastModified: new Date("2026-07-14T00:00:00.000Z"),
+        size: 10,
+      },
+    ],
+    destination({ retentionDays: 7 }),
+    now,
+  );
+
+  assert.deepEqual(keys, ["old.tar.gz"]);
+});
+
+test("maximum backup count keeps the newest objects", () => {
+  const keys = getExpiredObjectKeys(
+    [
+      {
+        key: "oldest.tar.gz",
+        lastModified: new Date("2026-07-10T00:00:00.000Z"),
+        size: 10,
+      },
+      {
+        key: "newest.tar.gz",
+        lastModified: new Date("2026-07-14T00:00:00.000Z"),
+        size: 10,
+      },
+      {
+        key: "middle.tar.gz",
+        lastModified: new Date("2026-07-12T00:00:00.000Z"),
+        size: 10,
+      },
+    ],
+    destination({ maxBackupCount: 2 }),
+    now,
+  );
+
+  assert.deepEqual(keys, ["oldest.tar.gz"]);
+});
+