design: minimal slashing

[just-mitch]

We need a design for a minimal slashing mechanism.

The required flow is simply:

• M of the previous N slots may have a proposals from their respective proposer to execute a particular payload
• The payload should be executable as soon as this M/N quorum is reached, (i.e. not need to go to "top level governance")
• The contract that executes the payload has the ability to slash assets that are used for staking
• the node will be configured to automatically vote for a proposal that "slashes" the committee in the event a reorg occurs
• the initial "slash" shouldn't actually slash, but should merely log out that a slash would have occurred.