feat: letter upload attachments#6572

ehsunahmadi wants to merge 6 commits into

matrix-org:mainmatrix-org/matrix-rust-sdk:mainfrom

p-num:letro/upload-thumbnail-hardening-2026-05-13p-num/matrix-rust-sdk-with-custom-data:letro/upload-thumbnail-hardening-2026-05-13Copy head branch name to clipboard