Mnemonic can be read by anyone on the server

[cloudnull]

As an operator I would like to have the mnemonic secret file to be read by the underlying process instead of being read and passed through as a string.

kyve      172091  0.0  1.8 842188 75264 ?        Ssl  13:41   0:02 node /usr/share/yarn/bin/yarn.js start
kyve      172115  0.0  0.0   2608   536 ?        S    13:42   0:00  \_ /bin/sh -c rimraf dist && tsc && node ./dist/src/index.js
kyve      172209  0.0  2.0 9638248 84064 ?       Sl   13:42   0:02      \_ /usr/bin/node ./dist/src/index.js
kyve      172220  0.5  2.8 21891908 115916 ?     Sl   13:42   0:42          \_ ./runtimes/@kyve/substrate/0.3.5/kyve-linux --poolId 17 --mnemonic ${MNEMONIC_STRING} --network korellia --keyfile ./secrets/arweave.json --initialStake ${STAKE_INT} --space 1073741824 --verbose

The current setup is functional, but it creates a trust situation when multiple operators may have access to a given machine. While it may be argued that operators with access to the machine should be trusted, I would argue that having the mnemonic as something globally visible by any user is exposing the service to risk which should be otherwise clamped down.