feat: add Akkudoktor feed-in provider (#1187)

The `FeedInTariffAkkudoktor` provider uses raw day-ahead market prices from
`https://api.akkudoktor.net/prices` as `feed_in_tariff_wh`. It does not add electricity import
charges or VAT. Published prices are extended to the configured prediction horizon with the same
seasonal ETS or median fallback used by the Akkudoktor electricity-price provider.

The Akkudoktor endpoint currently forwards hourly market prices from aWATTar. With a 15-minute
optimization interval, EOS holds each hourly price constant for its four quarter-hour slots. This
keeps the slot grid consistent but does not create genuine quarter-hour market prices.

Signed-off-by: Andreas Schmitz <akkudoktor.net>
Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>

docs/_generated/configfeedintariff.md

@@ -59,6 +59,7 @@
                "bidding_zone": "DE-LU"
            },
            "providers": [
+               "FeedInTariffAkkudoktor",
                "FeedInTariffEnergyCharts",
                "FeedInTariffFixed",
                "FeedInTariffImport"

docs/_generated/openapi.md

@@ -1,6 +1,6 @@
 # Akkudoktor-EOS
 
-**Version**: `v0.3.0.dev2607231331447302`
+**Version**: `v0.3.0.dev2607231372614323`
 
 <!-- pyml disable line-length -->
 **Description**: This project provides a comprehensive solution for simulating and optimizing an energy system based on renewable energy sources. With a focus on photovoltaic (PV) systems, battery storage (batteries), load management (consumer requirements), heat pumps, electric vehicles, and consideration of electricity price data, this system enables forecasting and optimization of energy flow and costs over a specified period.

docs/akkudoktoreos/prediction.md

@@ -208,15 +208,17 @@ data and rely on file/JSON imports only for initial setup.
 
 Prediction keys:
 
-- `feed_in_tarif_wh`: Feed in tarif per Wh (€/Wh).
-- `feed_in_tarif_kwh`: Feed in tarif per kWh (€/kWh)
+- `feed_in_tariff_wh`: Feed in tarif per Wh (€/Wh).
+- `feed_in_tariff_kwh`: Feed in tarif per kWh (€/kWh)
 
 Configuration options:
 
-- `feedintarif`: Feed in tariff configuration.
+- `feedintariff`: Feed in tariff configuration.
 
   - `provider`: Feed in tariff provider id of provider to be used.
 
+    - `FeedInTariffAkkudoktor`: Retrieves raw day-ahead market prices from the public
+      Akkudoktor API without
     - `FeedInTariffEnergyCharts`: Retrieves Energy-Charts day-ahead market prices and extends
       them to the configured prediction horizon when necessary.
     - `FeedInTariffFixed`: Provides fixed feed in tariff values.
@@ -227,6 +229,25 @@ Configuration options:
   - `feedintariffimport.import_file_path`: Path to the file to import feed in tariff forecast data from.
   - `feedintariffimport.import_json`: JSON string, dictionary of feed in tariff value lists.
 
+### FeedInTariffAkkudoktor Provider
+
+The `FeedInTariffAkkudoktor` provider uses raw day-ahead market prices from
+`https://api.akkudoktor.net/prices` as `feed_in_tariff_wh`. It does not add electricity import
+charges or VAT. Published prices are extended to the configured prediction horizon with the same
+seasonal ETS or median fallback used by the Akkudoktor electricity-price provider.
+
+The Akkudoktor endpoint currently forwards hourly market prices from aWATTar. With a 15-minute
+optimization interval, EOS holds each hourly price constant for its four quarter-hour slots. This
+keeps the slot grid consistent but does not create genuine quarter-hour market prices.
+
+```json
+{
+  "feedintariff": {
+    "provider": "FeedInTariffAkkudoktor"
+  }
+}
+```
+
 ### FeedInTariffEnergyCharts Provider
 
 The `FeedInTariffEnergyCharts` provider uses the raw Energy-Charts day-ahead market price as the