Issue Summary
When a Rovo app (Forge-based) posts a comment on a Confluence Cloud page that includes an ADF mention node referencing a valid, active user, the in-product notification flag preview renders the mention as @unknown instead of the user's display name. The comment body on the page itself renders the mention correctly.

Steps to Reproduce{}

1. Create a Rovo app (Forge-based) with an action that posts a comment using Create footer comment on a Confluence Cloud page
2. API call is made asAPP().
3. Configure the comment ADF payload to include a mention node referencing a valid, active user's accountId — e.g., { "type": "mention", "attrs": { "id": “***{}:7aaaca38-{}{}--{}{}{}***-be31683dde6b" }} (note: text attribute not set, as is typical for API-authored comments).

1. Trigger the Rovo agent to post the comment on any Confluence Cloud page.
2. Observe the in-product notification flag that appears (e.g., "RovoReview commented on a page just now") and its comment preview text.
3. Navigate to the page and open the actual comment.
4. Compare the mention rendering in the flag preview vs. the comment body.

Expected Results
The mention in the notification flag preview resolves to the user's display name (e.g., @TestUser), consistent with how it renders in the comment body on the page.

Actual Results
The notification flag preview renders the mention as @unknown, while the comment body on the page correctly displays @TestUser for the same mention node.

Workaround
Currently there is no known workaround for this behavior. A workaround will be added here when available