Module outbox 

Cloud outbox: async upload/delete of encrypted blobs.

The host enqueues upload entries (after writing a blob locally) and delete entries (tagged with the current sync seq). The sync cycle processes the outbox: uploads before push, deletes after pull.

Functions

process_deletes

Process pending deletes: remove cloud files whose deletion has been synced.

process_uploads

Process pending uploads: read local file, encrypt, write to cloud.