docs: split Attaching Files into OS and Pro guides with screenshots (#15104)

Replace the outdated, Findings-only add_files.md (which incorrectly
claimed image-only support) with an audience-scoped OS/Pro pair, following
the OS__/PRO__ convention already used by the risk_acceptance docs.

- OS__add_files.md: Manage Files workflow for Findings, Engagements, and
  Tests; corrected the supported file-type list to match
  DD_FILE_UPLOAD_TYPES; added fresh screenshots.
- PRO__add_files.md: documents the Pro UI flow (gear > Add File, the Files
  tab, and the row menu's Edit File Name / Delete File).
- Add OS_/PRO_ prefixed screenshots; preserve the old /add_files/ URL via
  an alias on the OS page.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: Maffooch

docs/assets/images/OS_finding_files_panel.png

@@ -0,0 +1,72 @@
+---
+title: "Attaching Files"
+description: "Upload screenshots, reports, or other supporting files to a Finding, Engagement, or Test in DefectDojo OS"
+audience: opensource
+weight: 3
+aliases:
+    - /triage_findings/findings_workflows/add_files/
+---
+
+You can attach files to a **Finding**, an **Engagement**, or a **Test** to provide
+supporting context — for example a proof-of-concept screenshot, a raw scanner report, a
+network diagram, or a spreadsheet that backs up a result.
+
+Each object keeps its own set of files, and you can attach **up to 10 files** to a single
+object.
+
+## Supported File Types
+
+By default the following extensions are accepted:
+
+```
+.txt  .pdf  .json  .xml  .csv  .yml  .png  .jpeg
+.sarif  .xlsx  .doc  .html  .js  .nessus  .zip  .fpr
+```
+
+Administrators can change this list with the `DD_FILE_UPLOAD_TYPES` environment variable.
+Uploading a file whose extension is not in the list is rejected by the form.
+
+Image files (such as `.png` and `.jpeg`) are rendered as a thumbnail preview, while other
+file types are shown with a generic file icon. In both cases, clicking the file downloads
+it.
+
+## How to Attach a File to a Finding
+
+1. Open the Finding you want to attach a file to.
+2. Open the actions menu (the **☰** button in the top-right of the Finding) and click
+   **Manage Files**.
+
+   ![Manage Files in the Finding actions menu](images/OS_manage_files_menu.png)
+
+3. On the **Add files** page, enter a **Title** for the file and choose the file from your
+   computer. You can add up to three files at a time; save and return to add more if needed.
+
+   ![The Manage Files upload form](images/OS_manage_files_form.png)
+
+4. Click **Save**.
+
+The file is then listed in the **Files** panel of the Finding. Image files appear as a
+thumbnail:
+
+![Files panel on a Finding showing an attached screenshot](images/OS_finding_files_panel.png)
+
+## Attaching Files to Engagements and Tests
+
+Engagements and Tests use the same **Manage Files** workflow:
+
+- On an **Engagement** or **Test** detail page, open the **Files** panel and click its edit
+  (pencil) button, then add files exactly as you would for a Finding.
+
+As with Findings, image attachments render as a thumbnail and other file types show a
+generic file icon.
+
+## Viewing and Downloading Files
+
+Attached files appear in the **Files** panel on the object's detail page. Click any file to
+download it. Access is permission-checked: a user must have **view** permission on the
+parent Finding, Engagement, or Test to download its files.
+
+## Deleting Files
+
+To remove a file, open **Manage Files** for the object, check the **Delete** checkbox under
+the file you want to remove, and click **Save**.

docs/assets/images/OS_manage_files_form.png

@@ -0,0 +1,51 @@
+---
+title: "Attaching Files"
+description: "Upload screenshots, reports, or other supporting files to a Finding, Engagement, or Test in DefectDojo Pro"
+audience: pro
+weight: 3
+---
+
+You can attach files to a **Finding**, an **Engagement**, or a **Test** to provide
+supporting context — for example a proof-of-concept screenshot, a raw scanner report, a
+network diagram, or a spreadsheet that backs up a result.
+
+Each object keeps its own set of files, and you can attach **up to 10 files** to a single
+object.
+
+## Supported File Types
+
+By default the following extensions are accepted:
+
+```
+.txt  .pdf  .json  .xml  .csv  .yml  .png  .jpeg
+.sarif  .xlsx  .doc  .html  .js  .nessus  .zip  .fpr
+```
+
+Administrators can change this list with the `DD_FILE_UPLOAD_TYPES` environment variable.
+Uploading a file whose extension is not in the list is rejected.
+
+## How to Attach a File to a Finding
+
+1. Open the Finding you want to attach a file to.
+2. Click the **gear (⚙) menu** in the top-right of the Finding and choose **Add File**.
+3. Enter a **Title** for the file and choose the file from your computer, then save.
+
+   ![The Add File action in the Finding gear menu, with the Files tab below](images/PRO_attach_files_menu.png)
+
+The same gear menu is available on **Engagement** and **Test** pages, so files can be
+attached to any of these objects the same way.
+
+## Viewing and Downloading Files
+
+Attached files are listed under the **Files** tab of the **Finding Overview** (and the
+equivalent section on Engagements and Tests). Click a file's title to download it.
+
+![The Files tab on a Finding listing an attached file](images/PRO_finding_files_tab.png)
+
+Access is permission-checked: a user must have **view** permission on the parent Finding,
+Engagement, or Test to download its files.
+
+## Deleting Files
+
+To remove a file, open the file's row menu (the **⋮** icon) in the **Files** tab and choose
+**Delete File**. The same menu also offers **Edit File Name** to rename an attachment.