[Bug] eSigner: new files from other users appear below older own files in API response and in UI

[krivtsova-arina]

Description

In the GET /api/files response, new files uploaded by other users are displayed below older files created by the current user.
This makes the list order incorrect in the UI and hides new items that require attention.

Steps to reproduce

Steps to reproduce the behavior:

1. User A uploads a few files
2. User B upload a new file and invite User A for signing
3. User A opens the file list

Example response

[
    {
        "id": "ef2e8789-03ea-4753-a585-a1b8840c4035",
        "name": "QA results by Geosemantica dated 26-12-2025.pdf",
        "displayName": "QA results by Geosemantica dated 26-12-2025.pdf",
        "description": "test",
        "mimeType": "application/pdf",
        "size": "342137",
        "md5Hash": "887fd0685554d29defe51d311e85d761",
        "ownerId": "fa11c089-e55b-4bd1-9c40-f5358b096e4d",
        "owner": {
            "id": "fa11c089-e55b-4bd1-9c40-f5358b096e4d",
            "name": "Arina",
            "ename": "@4bd72a27-45d2-57b4-b953-43d9ec431596"
        },
        "createdAt": "2026-01-20T13:24:14.552Z",
        "updatedAt": "2026-01-20T13:34:35.116Z",
        "status": "fully_signed",
        "totalSignees": 1,
        "signedCount": 1,
        "pendingCount": 0,
        "declinedCount": 0,
        "signatures": [
            {
                "id": "3e6febad-4b95-46d0-b998-a937fc1b89b6",
                "userId": "fa11c089-e55b-4bd1-9c40-f5358b096e4d",
                "user": {
                    "id": "fa11c089-e55b-4bd1-9c40-f5358b096e4d",
                    "name": "Arina",
                    "ename": "@4bd72a27-45d2-57b4-b953-43d9ec431596",
                    "avatarUrl": "https://firebasestorage.googleapis.com/v0/b/blabsy-msf.firebasestorage.app/o/images%2F%404bd72a27-45d2-57b4-b953-43d9ec431596%2F1CRsLsP0jsYD825ElHjg?alt=media&token=b7ae9dbd-ad09-46ed-8bc6-c2433ba621e9"
                },
                "createdAt": "2026-01-20T13:42:42.960Z"
            }
        ]
    },
    {
        "id": "c3a852f4-c6bc-4220-bbf9-bc0304ea4b38",
        "name": "favicon.png",
        "displayName": "favicon.png",
        "description": null,
        "mimeType": "image/png",
        "size": "2276",
        "md5Hash": "da7192420afc7cd94ddaa1676c9b4b65",
        "ownerId": "fa11c089-e55b-4bd1-9c40-f5358b096e4d",
        "owner": {
            "id": "fa11c089-e55b-4bd1-9c40-f5358b096e4d",
            "name": "Arina",
            "ename": "@4bd72a27-45d2-57b4-b953-43d9ec431596"
        },
        "createdAt": "2026-01-19T08:17:15.944Z",
        "updatedAt": "2026-01-19T08:17:15.944Z",
        "status": "partially_signed",
        "totalSignees": 2,
        "signedCount": 1,
        "pendingCount": 1,
        "declinedCount": 0,
        "signatures": [
            {
                "id": "e66f3f02-3654-4e7e-88bf-43f2571d9673",
                "userId": "fa11c089-e55b-4bd1-9c40-f5358b096e4d",
                "user": {
                    "id": "fa11c089-e55b-4bd1-9c40-f5358b096e4d",
                    "name": "Arina",
                    "ename": "@4bd72a27-45d2-57b4-b953-43d9ec431596",
                    "avatarUrl": "https://firebasestorage.googleapis.com/v0/b/blabsy-msf.firebasestorage.app/o/images%2F%404bd72a27-45d2-57b4-b953-43d9ec431596%2F1CRsLsP0jsYD825ElHjg?alt=media&token=b7ae9dbd-ad09-46ed-8bc6-c2433ba621e9"
                },
                "createdAt": "2026-01-19T08:17:57.774Z"
            }
        ]
    },
    {
        "id": "04d07c70-1e82-45bc-ae17-cf45d0997e58",
        "name": "17689166877445356130543892380938.jpg",
        "displayName": "17689166877445356130543892380938.jpg",
        "description": null,
        "mimeType": "image/jpeg",
        "size": "64509",
        "md5Hash": "3f7262e71533bec7e3109c4bd9f0961f",
        "ownerId": "dd13f289-b99b-4f5e-84f9-01958a05b71e",
        "owner": {
            "id": "dd13f289-b99b-4f5e-84f9-01958a05b71e",
            "name": "Android Test 2",
            "ename": "@ab666ba0-b5d6-56d4-9ebb-e3e66f3fb709"
        },
        "createdAt": "2026-01-20T13:45:06.855Z",
        "updatedAt": "2026-01-20T13:45:06.855Z",
        "status": "pending",
        "totalSignees": 2,
        "signedCount": 0,
        "pendingCount": 2,
        "declinedCount": 0,
        "signatures": []
    }
]

Expected behavior

New files should be ordered by creation time regardless of the author and displayed at the top of the list

Desktop:

• Device: any
• OS: any
• Browser: any