chore(backend): update config and user agent schema

- core/config.py: update application configuration
- schemas/user_agent.py: update user agent data schemas

server/src/app/core/config.py

@@ -71,6 +71,10 @@ class Settings(BaseSettings):
     ocr_timeout_seconds: int = Field(default=180, alias="OCR_TIMEOUT_SECONDS")
     ocr_max_file_size_mb: int = Field(default=20, alias="OCR_MAX_FILE_SIZE_MB")
     ocr_language: str = Field(default="ch", alias="OCR_LANGUAGE")
+    seed_demo_financial_records: bool = Field(
+        default=False,
+        alias="SEED_DEMO_FINANCIAL_RECORDS",
+    )
     ocr_text_detection_model: str = Field(
         default="PP-OCRv5_mobile_det",
         alias="OCR_TEXT_DETECTION_MODEL",