Discourage / block too many submissions of the same app

We are seeing often that a single app is submitted **a lot** of times in a short period of time.
This often happen with apps with geo restriction for instance.

We need to find a way to somehow prevent this, either by explaining better why the analysis fails (see https://github.com/Exodus-Privacy/exodus/issues/303) or by adding an additional message or even blocking if a single app is submitted too many times.

Start by reading issue #303 and tracing the app-submission and analysis-failure entry points to understand the existing feedback path. Define acceptance criteria for repeated submissions, including when to explain, warn, or block; the issue names no files or tests.

Written by the indexing model from the issue text.