These fields (and the MergedTokenLimits/MergedTokenWindow/MergedBudget/
MergedBudgetWindow/MergedRetention types) were never populated or read: the
wire shape sent to the proxy is guardrailConfig, and token/budget caps live on
Policy.Limits with retention on account Settings. Now that mergeGuardrails only
computes prompt capture, trim MergedGuardrails to that single field and delete
the orphaned types.