Suppress flow start page

When entering a flow, there is a start page prompting the user to start a new session or re-enter an existing session. We would like to add functionality to bypass this start page and immediately start a flow session.

Is it possible to suppress the start page?

Start by tracing the flow entry point and the code that displays the start page and creates or re-enters a flow session. Clarify the intended trigger and session behavior first; done means a supported path can bypass the page and immediately begin a flow session without breaking existing entry options.

Written by the indexing model from the issue text.