fix: delete issues, ePub reader (JSZip, linear cover, fonts), Pico dialog, UI polish

- Add POST /issues/<id>/delete route with file cleanup
- Fix ePub reader: add JSZip dependency, make cover linear in spine,
  inject system fonts into rendition
- Replace browser confirm() with Pico CSS dialog component
- Fix dashboard button sizing and consistency
- Add favicon, override Pico font stack to suppress Firefox warnings
- Compact issue action buttons

Made-with: Cursor

templates/issues.html

@@ -26,16 +26,16 @@
             <td>{{ item.article_count }}</td>
             <td>{{ item.issue.cover_method }}</td>
             <td>{{ item.issue.created_at.strftime('%b %d, %Y %H:%M') }}</td>
-            <td>
-                <a href="/issues/{{ item.issue.id }}/read" role="button" class="outline">
-                    Read
-                </a>
-                <a href="/issues/{{ item.issue.id }}/download" role="button" class="outline">
-                    Download
-                </a>
-                <form method="post" action="/issues/{{ item.issue.id }}/regenerate" style="display: inline;">
+            <td class="issue-actions">
+                <a href="/issues/{{ item.issue.id }}/read" role="button" class="outline">Read</a>
+                <a href="/issues/{{ item.issue.id }}/download" role="button" class="outline">Download</a>
+                <form method="post" action="/issues/{{ item.issue.id }}/regenerate">
                     <button type="submit" class="outline contrast">Regenerate</button>
                 </form>
+                <form method="post" action="/issues/{{ item.issue.id }}/delete" data-confirm-danger="true"
+                      onsubmit="event.preventDefault(); confirmAction('The ePub and cover files will also be removed.', this, 'Delete Issue?');">
+                    <button type="submit" class="outline btn-danger">Delete</button>
+                </form>
             </td>
         </tr>
         {% endfor %}