v0.3.6

merge: a capability exists from the first document filed in it

The two mains carry the same work under different commits, so this brings
across the one change this one does not have: inside a change, a capability
directory is read from the first document filed in it rather than from the
spec that arrives last, so an artifact written before the deltas is no longer
reported missing.

The only overlap was the line of comment naming the walk in board.mjs. The
conflicts card and everything reading the store at main are untouched.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>