resolveAndSubmitUris

Resolves uris from a system picker into Attachments and emits the result via submittedAttachments.

URIs whose content is inaccessible (e.g. cloud-backed files not downloaded to the device) are detected via a lightweight accessibility check and excluded from the result. When any URI is inaccessible, hasUnresolvedAttachments is set so the UI layer can display an appropriate message.

Parameters