"Assist prompt" action fails with "Internal Error" when choosing Pipeline (iOS 17.0.0)

When trying to configure the "Assist prompt" action in the iOS Shortcuts app, tapping the "Choose" button for the Pipeline parameter immediately triggers a system popup stating: "The action 'Assist prompt' could not run because an internal error occurred." This prevents the selection of any pipeline.
To Reproduce:
Steps to reproduce the behavior:
1. Open the Apple Shortcuts app.
2. Create a new shortcut.
3. Add the Home Assistant "Assist prompt" action.
4. Tap on "Choose" next to the Pipeline parameter.
5. The error popup appears immediately, and the pipeline list fails to load.
Expected behavior:
Tapping "Choose" should open a list of available Assist Pipelines retrieved from the Home Assistant server, allowing the user to select one.

Troubleshooting Steps Already Taken:
To rule out caching or webhook issues, I have performed a complete clean reset in the exact following order, but the issue persists:
1. Removed the server connection directly from within the Home Assistant iOS app.
2. Uninstalled the Home Assistant iOS app completely from the iPhone.
3. Accessed Home Assistant via a web browser (on a PC) and deleted the iPhone's entry from the ⁠Mobile App⁠ integration.
4. Restarted the iPhone.
5. Reinstalled the Home Assistant iOS app from the App Store and completed a fresh login/setup.
6. Created a brand new shortcut, added the "Assist prompt" action, tapped "Choose" for the Pipeline, and the exact same error occurred.
Environment details:
Device: iPhone 12 Pro Max
iOS Version: 17.0.0
Home Assistant Core Version: (2026.8.2)
Home Assistant iOS App Version: (2026.7.5)
Additional context:
It appears the App Intents framework might be failing to communicate between the Shortcuts app and the Home Assistant app on iOS 17.0.0, despite a completely fresh server connection and mobile app entity reset.

Reproduce the failure in Apple Shortcuts on iOS 17.0.0 using the Assist prompt action and the Pipeline parameter. Start by tracing the Home Assistant app's App Intents interaction when Choose is tapped, then verify that available Assist Pipelines can be retrieved and displayed without the Internal Error popup.

Written by the indexing model from the issue text.