docs: add onlyoffice

docs/.vitepress/usecase.en.ts

@@ -377,6 +377,10 @@ export const useCaseSidebar: DefaultTheme.Sidebar = {
               text: "Karakeep",
               link: "/use-cases/karakeep",
             },
+            {
+              text: "OnlyOffice",
+              link: "/use-cases/onlyoffice",
+            },
             {
               text: "Penpot",
               link: "/use-cases/penpot",

docs/.vitepress/usecase.zh.ts

@@ -377,6 +377,10 @@ export const useCaseSidebar: DefaultTheme.Sidebar = {
               text: "Karakeep",
               link: "/zh/use-cases/karakeep",
             },
+            {
+              text: "OnlyOffice",
+              link: "/zh/use-cases/onlyoffice",
+            },
             {
               text: "Penpot",
               link: "/zh/use-cases/penpot",

docs/use-cases/onlyoffice.md

@@ -0,0 +1,79 @@
+---
+outline: [2, 3]
+description: Use OnlyOffice on Olares to create, edit, upload, and export office files in a private browser-based workspace.
+head:
+  - - meta
+    - name: keywords
+      content: Olares, OnlyOffice, office suite, documents, spreadsheets, presentations, PDF editor, forms, export formats, self-hosted
+app_version: "1.0.10"
+doc_version: "1.0"
+doc_updated: "2026-06-03"
+---
+
+# Create and edit office files with OnlyOffice
+
+OnlyOffice is a browser-based office suite for working with text documents, spreadsheets, presentations, PDFs, and forms. It supports common Microsoft Office formats such as `.docx`, `.xlsx`, and `.pptx`, and provides a familiar editor experience directly from your Olares device.
+
+This guide covers the basic file workflow in the Olares app: creating new files, uploading existing documents, exporting them in multiple formats, and keeping your work inside your own Olares environment.
+
+## Install OnlyOffice
+
+1. Open Market and search for "OnlyOffice".
+
+   ![OnlyOffice](/images/manual/use-cases/onlyoffice.png#bordered)
+
+2. Click **Get**, then **Install**, and wait for installation to complete.
+
+## Use OnlyOffice
+
+Open OnlyOffice from Launchpad. The main page shows your existing files and provides controls for creating or uploading office documents.
+
+![OnlyOffice main page](/images/manual/use-cases/onlyoffice-main.png#bordered)
+
+### Create files
+
+1. On the main page, under **Create new**, select the file type you want to create:
+
+   - **Document**: Create a `.docx` text document.
+   - **Spreadsheet**: Create a `.xlsx` spreadsheet.
+   - **Presentation**: Create a `.pptx` slide deck.
+   - **PDF form**: Create a `.pdf` file.
+
+2. Start editing in the OnlyOffice editor. Your file is saved in the document list, where you can reopen it later for viewing or editing.
+
+### Export files
+
+After editing a file, go to **File** > **Download As** to download a copy in a desired format.
+
+| File type | Download formats |
+|:--|:--|
+| Document | `DOCX`, `PDF`, `ODT`, `DOTX`, `PDF/A`, `OTT`, `RTF`, `TXT`, `FB2`, `EPUB`,<br> `HTML`, `JPG`, `PNG` |
+| Spreadsheet | `XLSX`, `ODS`, `CSV`, `PDF`, `XLTX`, `OTS`, `XLSB`, `PDF/A`, `JPG`, `PNG` |
+| Presentation | `PPTX`, `PPSX`, `PDF`, `ODP`, `POTX`, `PDF/A`, `OTP`, `JPG`, `PNG` |
+| PDF | `DOCX`, `PDF`, `ODT`, `DOTX`, `OTT`, `RTF`, `TXT`, `FB2`, `EPUB`, `HTML`, <br>`JPG`, `PNG` |
+
+
+### Upload files
+
+1. On the main page, click **Upload file**.
+
+2. Select the target file from your computer.
+
+   OnlyOffice supports common office formats including `.docx`, `.xlsx`, `.pptx`, `.pdf`, `.odt`, `.ods`, and `.odp`.
+
+3. In the **File upload** dialog, wait for the file to load, convert, and finish loading editor scripts. Then choose how to open it:
+   - Click **Edit** to open the file for editing.
+   - Click **View** to open it in view-only mode.
+   - Click **Embedded View** to open the embedded viewer.
+
+   ![File upload dialog in OnlyOffice](/images/manual/use-cases/onlyoffice-file-upload-dialog.png#bordered)
+
+4. After the upload is complete, the file appears in the document list and can be opened again later.
+
+:::info
+ONLYOFFICE uses Office Open XML formats for editing. When you upload or open another format for editing, OnlyOffice might convert it first. Some formatting can change during conversion, especially for formats that do not support the same document features.
+:::
+
+## Learn more
+
+- [ONLYOFFICE documentation](https://helpcenter.onlyoffice.com/docs): Official ONLYOFFICE help center.

docs/zh/use-cases/onlyoffice.md

@@ -0,0 +1 @@
+<!--@include: ../../use-cases/onlyoffice.md-->