default env to production for the purpose of VPC installs

Author: kelsey-wong

services/chat-backend/.env.example

@@ -1 +1,2 @@
 OPENAI_API_KEY=sk-...
+ENVIRONMENT=development

services/chat-backend/src/core/config.py

@@ -17,7 +17,7 @@ class Settings(BaseSettings):
     model_config = SettingsConfigDict(env_file=get_dotenv_path(".env"), env_ignore_empty=True, extra="ignore")
 
     API_PREFIX: str = "/api"
-    ENVIRONMENT: Literal["development", "staging", "production"] = "development"
+    ENVIRONMENT: Literal["development", "staging", "production"] = "production"
     NUM_PROXIES: int