feat: Add comprehensive documentation suite and reorganize project structure

- Created complete documentation in docs/ directory
- Added PROJECT_OVERVIEW.md with feature highlights and getting started guide
- Added ARCHITECTURE.md with system design and technical details
- Added SECURITY.md with comprehensive security implementation guide
- Added DEVELOPMENT.md with development workflows and best practices
- Added DEPLOYMENT.md with production deployment instructions
- Added API.md with complete REST API documentation
- Added CONTRIBUTING.md with contribution guidelines
- Added CHANGELOG.md with version history and migration notes
- Reorganized all documentation files into docs/ directory for better organization
- Updated README.md with proper documentation links and quick navigation
- Enhanced project structure with professional documentation standards

router.php

@@ -0,0 +1,46 @@
+<?php
+// EasyStream Custom Page Router
+define('_ISVALID', true);
+
+$request_uri = $_SERVER['REQUEST_URI'];
+$path = parse_url($request_uri, PHP_URL_PATH);
+$path = trim($path, '/');
+
+// Handle custom pages
+switch ($path) {
+    case 'signin':
+        if (file_exists('signin.php')) {
+            include 'signin.php';
+            exit;
+        }
+        break;
+    case 'register':
+        if (file_exists('register.php')) {
+            include 'register.php';
+            exit;
+        }
+        break;
+    case 'browse':
+        if (file_exists('browse.php')) {
+            include 'browse.php';
+            exit;
+        }
+        break;
+    case 'upload':
+        if (file_exists('upload.php')) {
+            include 'upload.php';
+            exit;
+        }
+        break;
+    case 'logout':
+        if (file_exists('logout.php')) {
+            include 'logout.php';
+            exit;
+        }
+        break;
+    default:
+        // Fall back to main index
+        include 'index.php';
+        break;
+}
+?>