Remove deprecated demo, ingest, schema, and test parser files; add new LLM parser implementation and settings configuration

app/settings.py

@@ -0,0 +1,10 @@
+from pydantic_settings import BaseSettings
+
+class Settings(BaseSettings):
+    api_key: str
+    db_url: str
+
+    class Config:
+        env_file = ".env"
+
+settings = Settings()