feat: rename genetic optimization API fields to English (#675)

Rename the German field names of the genetic optimization API to
English with full backward compatibility:

- English names are canonical and documented in the OpenAPI schema;
  the German names are still accepted on input via validation aliases
  and re-emitted in responses as deprecated computed fields
- fix visualization receiving the raw German-keyed simulation dict
  (KeyError: load_wh_per_hour)
- rename internal German identifiers (optimize_ems, total_balance,
  battery_residual_value, self_consumption, extra_data keys)
- use amount instead of currency/euro in chart labels and schema
  descriptions; document currency handling (whole currency units,
  never cents) in the API description
- regenerate openapi.json and generated docs

Co-authored-by: Tobias Welz <tobias.wizneteu@gmail.com>

src/akkudoktoreos/prediction/elecprice.py

@@ -43,7 +43,7 @@ class ElecPriceCommonSettings(SettingsBaseModel):
         default=None,
         ge=0,
         json_schema_extra={
-            "description": "Electricity price charges [€/kWh]. Will be added to variable market price.",
+            "description": "Electricity price charges [amount/kWh]. Will be added to variable market price.",
             "examples": [0.21],
         },
     )