feat(attachments,security): migrate attachment processing to web worker and update CORS policy

- Add web worker for PDF attachment processing to improve performance and prevent UI blocking
- Create add-attachments.worker.js with TypeScript definitions for type safety
- Implement worker message handling with success and error responses
- Update nginx.conf to use Cross-Origin-Resource-Policy instead of Cross-Origin-Embedder-Policy for better cross-origin resource sharing
- Refactor add-attachments.ts to use worker-based processing with transferable objects
- Update main.ts to add home logo click handler for navigation
- Improve error handling with worker error event listener
- Add validation checks for PDF file availability before processing attachments

src/js/main.ts

@@ -29,9 +29,11 @@ const init = () => {
         simpleNav.innerHTML = `
           <div class="container mx-auto px-4">
             <div class="flex justify-start items-center h-16">
-              <div class="flex-shrink-0 flex items-center">
+              <div class="flex-shrink-0 flex items-center cursor-pointer" id="home-logo">
                 <img src="images/favicon.svg" alt="Bento PDF Logo" class="h-8 w-8">
-                <span class="text-white font-bold text-xl ml-2">BentoPDF</span>
+                <span class="text-white font-bold text-xl ml-2">
+                  <a href="index.html">BentoPDF</a>
+                </span>
               </div>
             </div>
           </div>