refactor: restructure project layout

- Move source files (app.js, styles.css) to src/ directory
- Move assets (UI.webp, UI-1.webp) to assets/ directory
- Update references in index.html and README.md"

README.md

@@ -2,8 +2,8 @@
 
 A powerful client-side AI image generation tool using OpenRouter API. Generate thumbnails, artwork, and creative images with multiple state-of-the-art models.
 
-![Imagen UI](UI.webp)
+![Imagen UI](assets/UI.webp)
-![Imagen UI-1](UI-1.webp)
+![Imagen UI-1](assets/UI-1.webp)
 
 ## ✨ Features
 
@@ -91,10 +91,10 @@ This is a **100% client-side application**:
 
 ```
 imagen/
-├── index.html      # Main UI structure
+├── src/            # Source code (JS/CSS)
-├── styles.css      # Premium dark theme styling
+├── assets/         # Images and design assets
-├── app.js          # Core logic + API integration
+├── index.html      # Main entry point
-└── README.md       # This file
+└── README.md       # Documentation
 ```
 
 ## 📜 License

index.html

@@ -5,7 +5,7 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Imagen</title>
-    <link rel="stylesheet" href="styles.css">
+    <link rel="stylesheet" href="src/styles.css">
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap" rel="stylesheet">
 </head>
 
@@ -161,7 +161,7 @@
         </div>
     </div>
 
-    <script src="app.js"></script>
+    <script src="src/app.js"></script>
 </body>
 
 </html>