Please address the comments from this code review:
## Overall Comments
- The new rateAt helper ignores its `t time.Time` parameter and always uses `time.Now()`—update it to use the passed‐in time for consistency and testability.
- The HTTP endpoints for smart-feed-in disabling (e.g. `/smartfeedindisablelimit`) use inconsistent casing compared to other routes—standardize on one naming convention for clarity.
- There’s a lot of duplicated logic between smart-cost and smart-feed-in handling—consider extracting shared behaviour into a common helper to reduce code duplication.

## Individual Comments

### Comment 1
<location> `core/site_tariffs.go:177` </location>
<code_context>
+	return site.GetTariff(usage).Type() != api.TariffTypePriceStatic
+}
+
+func rateAt(rates api.Rates, t time.Time) (api.Rate, error) {
+	rate, err := rates.At(time.Now())
+	if len(rates) > 0 && err != nil {
</code_context>

<issue_to_address>
rateAt ignores its time parameter and always uses time.Now()

The function should use the provided `t` parameter in `rates.At` to ensure correct evaluation at the intended time.
</issue_to_address>

### Comment 2
<location> `core/loadpoint/mock.go:925` </location>
<code_context>
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SetSmartCostLimit", reflect.TypeOf((*MockAPI)(nil).SetSmartCostLimit), limit)
 }

+// SetSmartFeedinLimit mocks base method.
+func (m *MockAPI) SetSmartFeedinLimit(limit *float64) {
+	m.ctrl.T.Helper()
</code_context>

<issue_to_address>
Avoid manual edits in a generated mock file

Regenerate the mock with mockgen to include the new methods, rather than editing the file manually.

Suggested implementation:

```golang

```

After removing the manual edit, you must run `mockgen` to regenerate `core/loadpoint/mock.go` with the updated interface that includes `SetSmartFeedinLimit`. This will ensure the mock is up-to-date and correctly generated.
</issue_to_address>