uSync: audited move to Jumoo org

Repo: KevinJump/uSync

Audited moving the repo from KevinJump/uSync to Jumoo/uSync: GitHub redirects/secrets carry over fine, but NuGet's OIDC trusted-publishing policy is bound to the exact repo owner and would break the next release unless updated in lockstep; found 7 files with hardcoded KevinJump URLs (plus a pre-existing wrong uSync8/core/main reference). Documented findings for when the move is actually planned in.