docs: add promotion flow for data apps (#741)

Co-authored-by: mintlify[bot] <109931778+mintlify[bot]@users.noreply.github.com>

Author: mintlify[bot]

guides/data-apps.mdx

@@ -132,6 +132,26 @@ Personal apps stay tied to whoever created them until they're moved into a space
   ![Clean Shot 2026 04 29 At 18 39 56@2x](/images/CleanShot-2026-04-29-at-18.39.56@2x.png)
 </Frame>
 
+## Promoting an app
+
+If you're building in a [preview project](/guides/developer/preview-projects), you can promote a data app into the preview's upstream (production) project once it's ready. This mirrors how chart and dashboard [promotion](/guides/how-to-promote-content) works: you iterate safely in preview, then push a snapshot to production.
+
+To promote an app:
+
+1. Open the app's **⋯** menu - either on the app card in a list, or in the chat header inside the app - and select **Promote**.
+2. In the confirmation dialog, review whether the action will **create** a new production app or **update** the existing linked one, and which space it will land in.
+3. Click **Promote**. When it finishes, you're taken to the promoted app in the production project.
+
+The first promotion creates a new app in the upstream project and links the two together. Every later promotion of the same preview app appends a new version to that linked production app, so production keeps a clean history of what was promoted and when. The latest ready version in preview is what gets snapshotted - in-progress builds are skipped.
+
+The app lands in a space that matches the source app's space by path. If no space with that path exists in the upstream project, Lightdash creates one. Personal apps (apps not in a space) are promoted as personal apps owned by the promoter.
+
+To promote, you need:
+
+- **Manage** access on the source data app in the preview project.
+- **Create** permission for data apps in the upstream project.
+- The preview project must have an upstream project configured under **Settings → Data ops**.
+
 ## Data context and the app model
 
 Data apps don't ship with their own copy of your data. They run inside a sandboxed iframe with no direct access to the Lightdash API, so every query the app wants to run is proxied through the Lightdash UI hosting the iframe.

guides/how-to-promote-content.mdx

@@ -66,3 +66,7 @@ If the dashboard or charts are in a space that doesn't exist in the upstream pro
 </Frame>
 
 Once the dashboard is promoted, you can click on the `success` banner to open a new tab into this dashboard in the `production project`.
+
+## Promote data apps
+
+You can also promote data apps from a preview project into their upstream project. See [Promoting an app](/guides/data-apps#promoting-an-app) in the data apps guide for details.