v0.56.0

BREAKING (behaviour): a node that declares NO output ports now publishes
nothing, and a chain it cuts says so. A terminal node can finally terminate.

Fixed

• Workflow::import() now READS a node's declared inputs / outputs, and
  export() writes them back (#20). It dropped them, with a comment claiming
  it was "matching the TS importer" — and that was measurably false: the
  TypeScript importer carries a document's ports onto data.outputs, and its
  exporter writes them precisely so a runtime in another language does not
  have to guess at a config-derived port set it cannot compute (switch_case
  cases, llm_router routes).

  So the one field written for this runtime was the one field this runtime
  threw away. Nothing failed; the fallback quietly substituted the kind's
  placeholder ports — a switch_case with cases alpha / beta reported
  case_a, case_b — so the undelivered-edge diagnostic named ports the node
  did not have and omitted the ones it did.

  fancy-flow (Python) and fancy-flow (Rust) had the identical gap and are
  fixed in the same release. Three states survive the round trip: absent means
  "not declared", [] means "explicitly no ports", a list means those ports.
  A port's type survives too — it was written on export and dropped on import,
  which made the round trip lossy in one direction.

Changed

• An empty output declaration means NO PORTS — from the node OR from the
  kind. activatedPorts refused an empty list coming from a kind and
  published out instead, so a terminal kind (log, output) could never
  actually terminate and a chain ran straight through it.

  That refusal was defensible while the alternative was a SILENT cut. The
  owner's ruling is strict, but a terminal node must be loud, so the cut now
  happens and announces itself.

  What you must DO: if a graph deliberately chains through a log or
  output node, or through any node declaring outputs: [], that chain now
  stops — and the run tells you which edge died. Give the node real output
  ports, or route around it. php artisan and every other entry point are
  unaffected.

• PortResolution::possible() honours the empty declaration too, and that is
  what makes the above safe. It had the SAME empty-to-out collapse, in the
  other of the two gates that shape a port set. Fixing only the runner would
  have been half a fix and the dangerous half: the node would publish nothing
  while this lookup still reported out as deliverable, leaving the
  undelivered-edge warning silent for exactly the edge that had just stopped
  delivering.

  A terminal node with nothing downstream stays silent — the warning is keyed on
  the EDGE, because a diagnostic that fires on correct graphs is how a real one
  stops being read.

• The pinned fixture set moves to particle-academy/fancy-conformance 0.29.
  flow/graph-runs row 0003's golden changed with the ruling (a chain through a
  log node no longer reaches the node after it), and flow/port-activation
  row 0303 is no longer skipped for node — it recorded this exact divergence and
  now passes everywhere.