feat: Download links for web server (#1039)

## Summary

* **What is the goal of this PR?** Add a link to files to download on
web server

## Additional Context

* There was already an api to download files, i just added a link to it
for files.

---

### AI Usage

Did you use AI tools to help write this code? **NO**

Addresses #621

---------

Co-authored-by: Eliz Kilic <elizk@google.com>

src/network/html/FilesPage.html

@@ -212,12 +212,14 @@
     .file-icon {
       margin-right: 8px;
     }
-    .folder-link {
+    .folder-link,
+    .file-link {
       color: var(--accent-color);
       text-decoration: none;
       cursor: pointer;
     }
-    .folder-link:hover {
+    .folder-link:hover,
+    .file-link:hover {
       color: var(--accent-hover-color);
       text-decoration: underline;
     }
@@ -872,7 +874,8 @@
           // Checkbox cell + file row
           fileTableContent += `<tr class="${file.isEpub ? 'epub-file' : ''}">`;
           fileTableContent += `<td><input type="checkbox" class="select-item" data-path="${encodeURIComponent(filePath)}" data-name="${escapeHtml(file.name)}" data-type="file"></td>`;
-          fileTableContent += `<td><span class="file-icon">${file.isEpub ? '📗' : '📄'}</span>${escapeHtml(file.name)}`;
+          fileTableContent += `<td><span class="file-icon">${file.isEpub ? '📗' : '📄'}</span>`;
+          fileTableContent += `<a rel="noopener noreferrer" target="_blank" href="/download?path=${encodeURIComponent(filePath)}" class="file-link">${escapeHtml(file.name)}</a>`;
           if (file.isEpub) fileTableContent += '<span class="epub-badge">EPUB</span>';
           fileTableContent += '</td>';
           fileTableContent += `<td>${file.name.split('.').pop().toUpperCase()}</td>`;