Add upgrade documentation for DefectDojo Version 2.58.x with notification template relocation details

Author: Maffooch

docs/content/releases/os_upgrading/2.58.md

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+---
+title: 'Upgrading to DefectDojo Version 2.58.x'
+toc_hide: true
+weight: -20260504
+description: Notification templates relocated under dojo/notifications/
+---
+
+## Notification templates relocated
+
+The notification domain has been consolidated under a new `dojo/notifications/` package. Notification templates that previously lived under `dojo/templates/` have been moved into `dojo/notifications/templates/notifications/`. Most templates can still be resolved by their existing lookup name, but the seven notification UI templates have been re-namespaced and any custom overrides of those need to be updated.
+
+### Channel templates (no action required for most users)
+
+The 62 channel templates under `alert/`, `mail/`, `msteams/`, `slack/`, `webhooks/`, and `webhooks_summary/` keep their existing template lookup names (e.g. `notifications/mail/scan_added.tpl`, `notifications/slack/sla_breach.tpl`). Existing customizations that override these by lookup name continue to work — only the on-disk source location has changed.
+
+### Notification UI templates (action required if customized)
+
+The seven notification UI templates have moved AND been re-namespaced from `dojo/...html` to `notifications/...html`:
+
+| Old lookup name | New lookup name |
+| --- | --- |
+| `dojo/alerts.html` | `notifications/alerts.html` |
+| `dojo/delete_alerts.html` | `notifications/delete_alerts.html` |
+| `dojo/notifications.html` | `notifications/notifications.html` |
+| `dojo/add_notification_webhook.html` | `notifications/add_notification_webhook.html` |
+| `dojo/edit_notification_webhook.html` | `notifications/edit_notification_webhook.html` |
+| `dojo/delete_notification_webhook.html` | `notifications/delete_notification_webhook.html` |
+| `dojo/view_notification_webhooks.html` | `notifications/view_notification_webhooks.html` |
+
+### Required Actions
+
+If you have overridden any of the seven notification UI templates above (for example by placing a custom `dojo/notifications.html` in your own templates directory), you must rename the override to the new `notifications/...html` path so it continues to take effect. No action is required for users who have not customized these templates, and no action is required for the channel `.tpl` templates regardless of customization.
+
+For more information, check the [Release Notes](https://github.com/DefectDojo/django-DefectDojo/releases/tag/2.58.0).