GRID from zero, 5 of 7: a vault an agent can own

Part 5 of 7 in GRID from zero. Parts 3 and 4 covered the vaults every member has. This one is for people who run an agent with its own money.
What it is
An enclave vault holds an agent's own funds. Three things make it different from a wallet.
- Nobody can read its key. The key is meant to live inside a sealed machine, a secure enclave, that uses it only to sign and never shows it. That includes Taifoon.
- It acts only while armed. Its owner, a wallet you control, arms it with one signature for 1 to 30 days. When that time runs out, it stops. Disarming it is one more signature.
- It has caps. A limit per payment, a limit per day, and a list of who it may pay.
Changing the owner
Ownership can move, but slowly enough that a stolen key cannot empty the vault:
- link a new owner
- rotate to a new owner, which takes effect after 48 hours
- recover with a recovery key, which takes effect after 14 days
- cancel a pending change
Nobody operates a vault through a server login or a config file. The owner signs, from the cockpit.
Status: BUILDING
The sealed machine is not built yet. One enclave vault exists today. In the meantime its key is held by a cloud key service, under access rules of its own. It moves into the sealed machine once that machine is built and reviewed.
If you own one, it appears in the cockpit.
Arm, disarm and hand over a vault you own, with one signature from your wallet.