graphify path: non-deterministic shortest-path route + calls label not backed by any stored edge #2074

Summary

graphify path "<A>" "<B>" returns a different shortest path on repeated, identical invocations against the same unmodified graph.json — and one of the observed paths displayed a --calls--> edge label that does not correspond to any stored edge with relation: "calls" in the graph data (there were zero calls-relation edges in the entire graph).

Steps to reproduce

1. Build a graph with /graphify (code + docs + papers corpus, ~490 nodes / ~1300 edges after build).
2. Run: graphify path "<node_id_A>" "<node_id_B>" where the shortest path is 4 hops with more than one route of equal length available.
3. Run the exact same command again (no changes to graph.json in between).

Observed

Run 1:

Shortest path (4 hops):
  <A> --rationale_for [EXTRACTED]--> ProductArgument <--references [EXTRACTED]-- ShuffleArgument --calls [EXTRACTED]--> ShuffleConsistencyArgument <--rationale_for [EXTRACTED]-- <B>

Run 2 (same command, same graph.json, no edits in between):

Shortest path (4 hops):
  <A> --rationale_for [EXTRACTED]--> ProductArgument --shares_data_with [EXTRACTED]--> VectorCommitment <--references [EXTRACTED]-- MultiExpArgumentSqrt <--rationale_for [EXTRACTED]-- <B>

Two different routes, both length 4, returned on identical repeated calls.

Additionally, when I went looking in graph.json for the edge that produced the --calls--> label from Run 1 (to fix what I initially assumed was a bad EXTRACTED edge), I found:

• Zero edges anywhere in the graph with "relation": "calls".
• Zero direct edges of any relation between the two class-level nodes (ShuffleArgument, ShuffleConsistencyArgument) shown adjacent in that path.

So the --calls--> shown in the CLI path output does not appear to come verbatim from a stored edge's relation field — it looks like either a display-layer synthesized/fallback label, or the path traversal is silently passing through an intermediate node (e.g. a shared/ambiguous generic node like .prove() or .verify() that appears at multiple source locations) whose real relation got mislabeled or collapsed in the printed output.

Why this matters

Users (and the agent driving /graphify) reasonably treat EXTRACTED-confidence output as ground truth per the skill's own Honesty Rules ("never invent an edge"). A shortest-path command that (a) isn't deterministic between identical calls, and (b) can print a relation label that doesn't trace back to any real stored edge, undermines that guarantee specifically for the path command's output — someone could act on --calls--> as fact when no such edge exists.

Environment

• graphifyy 0.9.21
• Windows 11, Git Bash, Python via uv tool
• Graph: ~490 nodes, ~1300 edges, 21 communities, undirected

Suggested fix directions

• Make path's tie-breaking among equal-length shortest paths deterministic (e.g. stable sort by node id).
• When printing an edge in the path, read the relation directly from the stored edge object rather than any synthesized/fallback label, and if multiple parallel edges exist between the same two nodes, either print all relations or pick deterministically (not silently pick one that doesn't match what's stored).