fix: dynamically parse all census field appends

Replace hardcoded census year parsing (census2010, census2020, census2023)
with dynamic detection and parsing of any census field returned by the API.

Changes:
- Modified _parse_fields() to automatically detect and parse any field
  matching the pattern "census" + digits (e.g., census2024, census2025)
- Removed slots=True from GeocodioFields to allow dynamic field passing
  via **kwargs (backwards compatible, negligible performance impact)
- Only parses census fields that are defined in the GeocodioFields model

Benefits:
- Fixes issue where census2024 was not being parsed
- Future-proof: new census years only require adding a field definition
  to GeocodioFields, no changes needed to parsing logic
- Maintains backwards compatibility with all existing census fields

Fixes #12

Author: MiniCodeMonkey

src/geocodio/client.py

@@ -443,20 +443,17 @@ def _parse_fields(self, fields_data: dict | None) -> GeocodioFields | None:
                 for district in fields_data["school"]
             ]
 
-        census2010 = (
-            CensusData.from_api(fields_data["census2010"])
-            if "census2010" in fields_data else None
-        )
-
-        census2020 = (
-            CensusData.from_api(fields_data["census2020"])
-            if "census2020" in fields_data else None
-        )
-
-        census2023 = (
-            CensusData.from_api(fields_data["census2023"])
-            if "census2023" in fields_data else None
-        )
+        # Dynamically parse all census fields (e.g., census2010, census2020, census2024, etc.)
+        # This supports any census year returned by the API
+        from dataclasses import fields as dataclass_fields
+        valid_field_names = {f.name for f in dataclass_fields(GeocodioFields)}
+
+        census_fields = {}
+        for key in fields_data:
+            if key.startswith("census") and key[6:].isdigit():  # e.g., "census2024"
+                # Only include if it's a defined field in GeocodioFields
+                if key in valid_field_names:
+                    census_fields[key] = CensusData.from_api(fields_data[key])
 
         acs = (
             ACSSurveyData.from_api(fields_data["acs"])
@@ -515,9 +512,6 @@ def _parse_fields(self, fields_data: dict | None) -> GeocodioFields | None:
             state_legislative_districts=state_legislative_districts,
             state_legislative_districts_next=state_legislative_districts_next,
             school_districts=school_districts,
-            census2010=census2010,
-            census2020=census2020,
-            census2023=census2023,
             acs=acs,
             demographics=demographics,
             economics=economics,
@@ -528,6 +522,7 @@ def _parse_fields(self, fields_data: dict | None) -> GeocodioFields | None:
             provriding=provriding,
             provriding_next=provriding_next,
             statcan=statcan,
+            **census_fields,  # Dynamically include all census year fields
         )
 
     # @TODO add a "keep_trying" parameter to download() to keep trying until the list is processed.

src/geocodio/models.py

@@ -283,7 +283,7 @@ class FFIECData(ApiModelMixin):
     extras: Dict[str, Any] = field(default_factory=dict, repr=False)
 
 
-@dataclass(slots=True, frozen=True)
+@dataclass(frozen=True)
 class GeocodioFields:
     """
     Container for optional 'fields' returned by the Geocodio API.