Make morph reach secrets via a local symlink

See https://whetstone.privatestorage.io/privatestorage/PrivateStorageio/-/merge_requests/87#note_13306 for the why and how.

changed the description

mentioned in commit 51b981bd

mentioned in merge request !93 (merged)

closed with merge request !93 (merged)

closed with commit 51b981bd

mentioned in commit 13d8f91d