feat: introduce pydantic-settings for config definition and validation (#5202)

Co-authored-by: -LAN- <laipz8200@outlook.com>

api/configs/app_configs.py

@@ -0,0 +1,42 @@
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+from configs.deploy import DeploymentConfigs
+from configs.enterprise import EnterpriseFeatureConfigs
+from configs.extra import ExtraServiceConfigs
+from configs.feature import FeatureConfigs
+from configs.middleware import MiddlewareConfigs
+from configs.packaging import PackagingInfo
+
+
+class DifyConfigs(
+    # based on pydantic-settings
+    BaseSettings,
+
+    # Packaging info
+    PackagingInfo,
+
+    # Deployment configs
+    DeploymentConfigs,
+
+    # Feature configs
+    FeatureConfigs,
+
+    # Middleware configs
+    MiddlewareConfigs,
+
+    # Extra service configs
+    ExtraServiceConfigs,
+
+    # Enterprise feature configs
+    # **Before using, please contact business@dify.ai by email to inquire about licensing matters.**
+    EnterpriseFeatureConfigs,
+):
+
+    model_config = SettingsConfigDict(
+        # read from dotenv format config file
+        env_file='.env',
+        env_file_encoding='utf-8',
+
+        # ignore extra attributes
+        extra='ignore',
+    )