[add]: code refractoring and cleanup

app/__init__.py

@@ -0,0 +1,26 @@
+from flask import Flask
+import os
+from .extensions import db, migrate
+
+
+"""
+Salary Analytics Package
+A package for analyzing and predicting salary patterns from transaction data.
+"""
+
+__version__ = "0.1.0" 
+
+
+def create_app():
+    app = Flask(__name__)
+    app.config.from_object('salary_analytics.config')
+
+    # Initialize extensions
+    db.init_app(app)
+    migrate.init_app(app, db)
+
+    # Register blueprints or CLI commands here if needed
+    from .commands import commands
+    app.cli.add_command(commands.upload_xls_cli)
+
+    return app