refactor: assembling the app features in modular way (#9129)

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

api/extensions/ext_database.py

@@ -1,6 +1,8 @@
 from flask_sqlalchemy import SQLAlchemy
 from sqlalchemy import MetaData
 
+from dify_app import DifyApp
+
 POSTGRES_INDEXES_NAMING_CONVENTION = {
     "ix": "%(column_0_label)s_idx",
     "uq": "%(table_name)s_%(column_0_name)s_key",
@@ -13,5 +15,5 @@ metadata = MetaData(naming_convention=POSTGRES_INDEXES_NAMING_CONVENTION)
 db = SQLAlchemy(metadata=metadata)
 
 
-def init_app(app):
+def init_app(app: DifyApp):
     db.init_app(app)