phsl / new-api

* Introduced `showWithRecharge` switch in the actions bar to display model prices based on recharge cost.
* Added a `Select` dropdown (USD / CNY) that appears only when the recharge-price mode is enabled.
* Implemented `displayPrice()` helper to:
  * Convert USD prices to recharge prices using `status.price` and `status.usd_exchange_rate`.
  * Format output according to the selected currency.
* Updated price rendering for both quota types to use the new helper and respect K/M unit conversion.
* Removed the old currency switch from the header, retaining only the K/M unit toggle.
* Extended `SearchAndActions` memo dependencies; imported `Select` from Semi UI.
* Minor refactors and comment clean-up.

No breaking changes.