dagr producer — write the run, prove the run

You are the producer: the single writer of a run file that dagr view renders live. dagr is a representation kernel: you assert task truth, and it derives only defined view signals from those facts. Missing or wrong facts still produce a missing or wrong graph; there is no workflow engine to repair it.

Contract version: "dagr": 3 (v1/v2 files remain readable; write v3 for new runs).

Find your validator (before you write anything)

The check loop below is the only feedback you get, so resolve the dagr binary FIRST and stop if you can't: