Reverts the earlier per-rate pricing_mode column in favor of extending Lunar's existing charge_by field (cart_total/weight) with a third "live" option, gated by a SupportsLivePricing capability check on the driver. Adds a shared ResolvesFixedPricing trait so any carrier driver can fall back to Lunar's normal price-break resolution, matching the vendor ShipBy driver's own charge_by handling instead of introducing a separate mechanism. Also fixes an incorrect Get() path in the admin form that silently hid the new "live" option.
arvanitakis