sync_branch (B1, 250be5c2) is a git-only rebase+force-push verb (composes=(),
no DB transition, side_effects=()) but was never registered in the tracing
parity tables, so test_every_intent_verb_has_a_tracing_decision failed.
Mirrors open_pr: a mechanical git op with inline preconditions (ownership),
no journal/plan rationale required.