The inner ring of the schedule slice, added on its own so it can be read
as domain modelling rather than as a diff against the old implementation:
two aggregates with their state machines, the policy value object, the
output ports the service depends on, and the errors it raises.
Nothing wires it up yet -- no existing code path changes. The service is
exercised end to end against in-memory fakes, which is what makes the
rules (overlap policy, lease handling, which write owns which timestamp)
assertable without a database at all.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Introduces the ports-and-adapters standard new backend modules are
expected to follow, plus the two pieces that make it more than prose:
`deerflow/domain/` as the inner-ring namespace, and an AST test that
fails when anything under it imports infrastructure.
The spec is normative rather than descriptive -- the existing modules
predate it, so the test guards the namespace, not the whole backend.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>