feat: add billing switch. (#1789)

Co-authored-by: StyleZhang <jasonapring2015@outlook.com>

api/config.py

@@ -55,6 +55,8 @@ DEFAULTS = {
     'OUTPUT_MODERATION_BUFFER_SIZE': 300,
     'MULTIMODAL_SEND_IMAGE_FORMAT': 'base64',
     'INVITE_EXPIRY_HOURS': 72,
+    'BILLING_ENABLED': 'False',
+    'CAN_REPLACE_LOGO': 'False',
     'ETL_TYPE': 'dify',
 }
 
@@ -279,6 +281,8 @@ class Config:
 
         self.ETL_TYPE = get_env('ETL_TYPE')
         self.UNSTRUCTURED_API_URL = get_env('UNSTRUCTURED_API_URL')
+        self.BILLING_ENABLED = get_bool_env('BILLING_ENABLED')
+        self.CAN_REPLACE_LOGO = get_bool_env('CAN_REPLACE_LOGO')
 
 
 class CloudEditionConfig(Config):