Variable: KEY_PURPOSE_PATTERN
constKEY_PURPOSE_PATTERN:"^[a-z][a-z0-9-]{0,62}$"='^[a-z][a-z0-9-]{0,62}$'
Defined in: packages/contracts/src/schemas/audit-actions.ts:238
A key's purpose, as signing-key.generate records it: a lowercase code such as
trust-chain, the only purpose in slice 2 (D2.4). A pattern rather than a list,
because the key policy gains purposes with slice 3's credential keys and an
enumeration here would make each one a new payload version.