Housekeeping: update stale comments after rebase on main

- UtilityConfig: update comment to reflect that vat/fees/markup are now
  validated by validate_provider_required_fields, not by downstream code
- dynamictariff.py: add note that required_fields checks are secondary
  safety guards — primary validation is now in Pydantic at load time

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: MaStr

src/batcontrol/config_model.py

@@ -105,9 +105,9 @@ class UtilityConfig(BaseModel):
     type: str
     apikey: Optional[str] = None
     url: Optional[str] = None
-    # vat/fees/markup are Optional so that downstream required_fields checks
-    # (in dynamictariff.py) can detect missing config for providers that need them.
-    # With exclude_none=True, absent keys won't appear in the output dict.
+    # vat/fees/markup are Optional; validate_provider_required_fields below
+    # enforces them for known providers at config load time.
+    # With exclude_none=True, unset fields won't appear in the output dict.
     vat: Optional[float] = None
     fees: Optional[float] = None
     markup: Optional[float] = None

src/batcontrol/dynamictariff/dynamictariff.py

@@ -42,6 +42,8 @@ def create_tarif_provider(config: dict, timezone,
         """
         selected_tariff = None
         provider = config.get('type')
+        # Note: required-field checks below are secondary safety guards.
+        # Primary validation happens at config load time via Pydantic (config_model.py).
 
         if provider.lower() == 'awattar_at':
             required_fields = ['vat', 'markup', 'fees']