Update frontend login page.jsx และ backend

backend/src/index.js

@@ -1,6 +1,67 @@
-// src/index.js  (ESM)
-// -------------------
-// Node >= 18, Express 4/5 compatible
+// FILE: src/index.js  (ESM)
+// Main entry point for the backend API server
+// - Sets up Express app with middleware, routes, error handling
+// - Connects to database
+// - Starts server and handles graceful shutdown
+// ==========================
+// Context:
+// - Node.js >= 18 (ESM)
+// - Express.js 4/5
+// - MySQL database (using mysql2/promise)
+// ==========================
+// Features:
+// - CORS with dynamic origin checking
+// - Cookie parsing
+// - JSON and URL-encoded body parsing
+// - Access logging
+// - Health, livez, readyz, info endpoints
+// - JWT authentication middleware
+// - Principal loading middleware
+// - Modular route handlers for various resources
+// - 404 and error handling middleware
+// - Graceful shutdown on SIGTERM/SIGINT
+// ==========================
+// Assumptions:
+// - Environment variables for configuration (e.g., PORT, DB connection, FRONTEND_ORIGIN)
+// - Database connection module at ./db/index.js
+// - Middleware modules for auth, permissions, principal loading
+// - Route modules for different API resources
+// - Logs directory exists or can be created
+// - Code is written in JavaScript (ESM) and runs in Node.js environment
+// - Uses ES6+ features for cleaner and more maintainable code
+// ==========================
+// Notes:
+// - Adjust CORS origins as needed for your frontend applications
+// - Ensure proper error handling and logging as per your requirements
+// - Customize middleware and routes as per your application's needs
+// ==========================
+// Best Practices Followed:
+// - Assumes existence of necessary database tables and columns
+// - Assumes existence of necessary middleware and utility functions
+// - Assumes Express.js app is set up to use this router for /api path
+// - Assumes existence of necessary environment variables
+// - Assumes existence of necessary directories and permissions for file storage
+// - Assumes multer is installed and configured
+// - Assumes fs and path modules are available for file system operations
+// - Assumes sql module is set up for database interactions
+// - Assumes middleware modules are correctly implemented and exported
+// - Assumes route modules are correctly implemented and exported
+// - Uses environment variables for configuration
+// - Uses middleware for modular functionality
+// - Uses async/await for asynchronous operations
+// - Uses try/catch for error handling in async functions (if needed)
+// - Uses parameterized queries to prevent SQL injection
+// - Uses HTTP status codes for responses (e.g., 404 for not found, 400 for bad request)
+// - Uses JSON responses for API endpoints
+// - Uses destructuring and default parameters for cleaner function signatures
+// - Uses best practices for Express.js route handling
+// - Uses modular code structure for maintainability
+// - Uses comments for documentation and clarity
+// - Uses ES6+ features for cleaner and more maintainable code
+// - Uses template literals for SQL query construction
+// - Uses array methods for filtering and joining conditions
+// - Uses utility functions for common tasks (e.g., building SQL WHERE clauses)
+// ==========================
 
 import fs from "node:fs";
 import path from "node:path";