added comments and fixed some wrong text.

app/__init__.py

@@ -1,18 +1,30 @@
+"""Application factory and shared Flask extensions.
+
+This file creates the Flask application, configures the database and login
+manager, imports the data models so SQLAlchemy knows about them, and registers
+the route blueprints used by the project.
+"""
+
 import os
 
 from flask import Flask
 from flask_login import LoginManager
 from flask_sqlalchemy import SQLAlchemy
 
+# Shared extension instances are created once here and attached to the app
 db = SQLAlchemy()
 login_manager = LoginManager()
 
 
 def create_app():
+    """Build and configure the Flask application instance."""
     app = Flask(__name__)
 
+    # Build an absolute path to the application directory so the SQLite
+    # database file can be referenced reliably from any working directory.
     BASE_DIR = os.path.abspath(os.path.dirname(__file__))
 
+    # Core Flask and SQLAlchemy configuration.
     app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///" + os.path.join(BASE_DIR, "app.db")
     app.config["SECRET_KEY"] = os.getenv("SECRET_KEY", "dev-secret-key")
     app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
@@ -20,22 +32,27 @@ def create_app():
     app.config["REMEMBER_COOKIE_HTTPONLY"] = True
     app.config["SESSION_COOKIE_SAMESITE"] = "Lax"
 
+    # Connect the shared extension objects to this specific app instance.
     db.init_app(app)
     login_manager.init_app(app)
     login_manager.login_view = "login.login"
     login_manager.login_message_category = "info"
 
+    # Import the models before create_all() so SQLAlchemy has the table
     from .models.user import User
     from .models.gamestate import GameState
     from .models.login_attempt import LoginAttempt
 
+    # Create any database tables that do not exist yet.
     with app.app_context():
         db.create_all()
 
     @login_manager.user_loader
     def load_user(user_id):
+        """Reload the logged-in user from the session-stored user id."""
         return db.session.get(User, int(user_id))
 
+    # Import and register the blueprints that contain the route handlers.
     from .routes.login_routes import login_bp
     from .routes.main_routes import main_bp