creating/interacting with random scratchpad/graphentry/pointer by passing the private key as hex encoded string as header param

the idea is that creating/interacting with random scratchpad/graphentry/pointer by passing the private key as hex encoded string as header param would enable a lot of additional use cases where shared access to those data types would be useful.

currently dweb derives from a global secret with app-id and object-id which is great for recovery without the need to store a list of private keys somewhere but prevents people from
- just creating a scratchpad to share with someone else to modify it
- tell someone "I expect your answer on that graphEntry key/address" and that other party being able to asynchronously answer at some later point in time (autonomi mail system; you create a receiving branch for every contact you invite to write you)

this is not super urgent - I would love to see deterministic ports and https sooner.
but e.g. for a public billboard app where anybody can just modify/update the content I would love to have this feature ... just hard-coding some private-keys into the app (or maybe a derivation rule if the scratchpad is at its max_count to prevent people from breaking it)