Provenance and Replay

Every Stargraph run emits a trace that is sufficient to replay the run: IR hash, plugin versions, RNG seeds, tool inputs/outputs, and Fathom decisions. Provenance is non-negotiable — a run without a complete trace is treated as an error, not a warning.

What is captured

• IR hash — content-addressed identity of the graph.
• Plugin set — distribution name, version, and api_version for every registered plugin.
• Decision log — Fathom rule firings, in order, with fact snapshots.
• I/O envelopes — content-addressed payloads for all node inputs and outputs.

TODO: cross-link the replay CLI and the trace schema once they ship.