willchen96 unbreaks shared projects and opens up where Mike can store files

Mike's project-sharing feature had a hidden fault. Anyone who had a project shared with them by a colleague would find their project list simply refused to load - a flaw in how the database queried the sharing records, invisible until you were on the receiving end of a share. willchen96 traced it to both places that ask "which projects can this person see" and corrected them together, so the collaboration path works end to end rather than half-fixed.

The second change loosens which file storage Mike will talk to. Out of the box it assumed Amazon's own S3 service; the new setting lets it work with any S3-compatible store, including the kind teams run locally for development or to keep data on their own infrastructure. Small flag, broad consequence: Mike is no longer married to one cloud vendor for document storage.