feat: Update year normalization logic to reflect US-style pronunciation for years 1100-1999; adjust related tests for consistency

abogen/web/routes/settings.py

@@ -92,7 +92,8 @@ def update_settings() -> ResponseReturnValue:
     for key in _NORMALIZATION_BOOLEAN_KEYS:
         current[key] = _extract_checkbox(key, bool(current.get(key, True)))
     for key in _NORMALIZATION_STRING_KEYS:
-        current[key] = (form.get(key) or "").strip()
+        if hasattr(form, "__contains__") and key in form:
+            current[key] = (form.get(key) or "").strip()
 
     # Integrations
     current["integrations"] = current.get("integrations", {})

abogen/web/routes/utils/settings.py

@@ -316,6 +316,12 @@ def normalize_setting_value(key: str, value: Any, defaults: Dict[str, Any]) -> A
             if normalized_mode in {"off", "spacy", "llm"}:
                 return normalized_mode
         return defaults[key]
+        if key == "normalization_numbers_year_style":
+            if isinstance(value, str):
+                normalized_style = value.strip().lower()
+                if normalized_style in {"american", "off"}:
+                    return normalized_style
+            return defaults[key]
     if key == "llm_context_mode":
         if isinstance(value, str):
             normalized_scope = value.strip().lower()