feat: expose workflow state events and persist signal transitions

internal/storage/mysql/workflow_signal_source.go

@@ -175,9 +175,8 @@ func claimWorkflowSignal(ctx context.Context, tx *sql.Tx, g *workflowGraph, w *w
 	v.Revision++
 	v.Disposition = "WAIT_MATCHED"
 	v.ConsumedWaitID = &w.id
-	return nil
+	return emitWorkflowSignalTransition(ctx, tx, g.view.NamespaceID, g.view.ID, v.ID, v.Revision, string(v.State), v.Disposition, v.ConsumedWaitID)
 }
 func rejectOtherWorkflowSignals(ctx context.Context, tx *sql.Tx, g *workflowGraph, row *workflowStep, sequence uint32, reason string, now time.Time) error {
-	_, err := tx.ExecContext(ctx, `UPDATE weave_signals SET state='REJECTED',disposition=?,revision=revision+1,updated_at=? WHERE namespace_id=? AND workflow_id=? AND target_step_key=? AND target_activation_sequence=? AND state='PENDING'`, reason, now, g.view.NamespaceID, g.view.ID, row.view.Key, sequence)
-	return err
+	return rejectPendingWorkflowSignals(ctx, tx, g, ` AND s.target_step_key=? AND s.target_activation_sequence=?`, []any{row.view.Key, sequence}, reason, now)
 }