fix: Fixed OO integration for documents in share drives

[shepilov]

When Bob opens a document from Alice’s shared drive, the Drive app needs the OnlyOffice config block to initialize the editor. Before this change, we explicitly nulled that block.

Without OnlyOffice, the Drive app falls back to “open as shared file on Alice” behavior instead of opening the OnlyOffice editor.

{
    "onlyoffice": {
      "url": "https://onlyoffice.example.com",
      "token": "eyJhbGciOiJ...",
      "documentType": "word",
      "document": {
        "filetype": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
        "key": "doc-key-3f6b0c2e",
        "title": "Project Plan.docx",
        "url": "https://alice.localhost:8080/files/downloads/secret123/Project%20Plan.docx",
        "info": {
          "owner": "Alice",
          "uploaded": "2026-02-11 10:35 AM"
        }
      },
      "editor": {
        "callbackUrl": "https://alice.localhost:8080/office/callback",
        "lang": "ru",
        "mode": "edit",
        "customization": {
          "compactHeader": true,
          "customer": {},
          "feedback": false,
          "forcesave": true,
          "goback": false
        }
      }
    }
}

[taratatach]

the Drive app falls back to “open as shared file on Alice” behavior

That's the expected behavior for shared office documents. Since the doc only exists on Alice's instance, why would we want a different behavior here?