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

src/routes/issues.py

@@ -37,6 +37,15 @@ def download(issue_id):
     )
 
 
+@issues_bp.route("/issues/<int:issue_id>/epub")
+def epub_file(issue_id):
+    issue = Issue.query.get_or_404(issue_id)
+    if not os.path.exists(issue.epub_path):
+        flash("ePub file not found.", "error")
+        return redirect(url_for("issues.index"))
+    return send_file(issue.epub_path, mimetype="application/epub+zip")
+
+
 @issues_bp.route("/issues/<int:issue_id>/cover")
 def cover_image(issue_id):
     issue = Issue.query.get_or_404(issue_id)
@@ -73,6 +82,22 @@ def read(issue_id):
     )
 
 
+@issues_bp.route("/issues/<int:issue_id>/delete", methods=["POST"])
+def delete(issue_id):
+    issue = Issue.query.get_or_404(issue_id)
+
+    if issue.epub_path and os.path.exists(issue.epub_path):
+        os.remove(issue.epub_path)
+    if issue.cover_path and os.path.exists(issue.cover_path):
+        os.remove(issue.cover_path)
+
+    db.session.delete(issue)
+    db.session.commit()
+
+    flash("Issue deleted.")
+    return redirect(url_for("issues.index"))
+
+
 @issues_bp.route("/issues/<int:issue_id>/regenerate", methods=["POST"])
 def regenerate(issue_id):
     issue = Issue.query.get_or_404(issue_id)