* 🧾 fix: Honor Disabled Transactions on the Assistants Usage Path
Thread the resolved transactions config through `recordUsage` from each of
its callers, so `transactions.enabled: false` is honored on the assistants
token spend path.
* 🧾 fix: Thread the transactions config through the vision-request caller
Address review: `ToolService.processVisionRequest` also records usage without
the resolved config, and `recordUsage`'s documented return type did not match
the function.
* 🧾 fix: Set the resolved transactions config after the usage spread
- provider usage could carry a `transactions` key that overwrote the trusted value
- matches the ordering the other `recordUsage` callers already use
