It sounded like a really simple request: "Is it easy to add a search filter for 'My posts'?". In other words, add a search result facet for posts by the current (logged in) user through the Apache Solr Search Integration module APIs?
But then the wheels start turning - we want not just one blind link, but a real facet link that tells us how many results we'll get. Also, if we are filtering by 'My posts' then we probably have an equal use case for the opposite filter 'Posts not by me'. So we really need a facet block with two links and facets counts.