fix(web): add comic delete UI and fix container Cloudflare bypass for #6

- Add delete button (SVG X, hover-reveal) and confirmation modal to comic cards
- Add DELETE /api/comics/delete endpoint with path traversal protection
- Fix container downloads: delegate Cloudflare-blocked requests to FlareSolverr
  (headless Chrome sidecar) instead of retrying with Go HTTP client, whose Linux
  TCP fingerprint is flagged by Cloudflare even with network_mode: host
- Add FlareSolverr service to docker-compose; inject FLARESOLVERR_URL env var
- Add diagnostic logging to BatcaveBizMarkup request flow
- Trim URL whitespace before storing in download job
- Guard Archive() against empty filelist; fix runJob error-check ordering

comic/archive.go

@@ -23,6 +23,9 @@ func (a ArchiveError) Error() string {
 // It takes no parameters.
 // Returns an error if the operation fails.
 func (c *Comic) Archive() error {
+	if len(c.Filelist) == 0 {
+		return nil
+	}
 
 	outputPath := filepath.Join(c.LibraryPath, c.Title, c.Title+".cbz")
 	err := os.MkdirAll(filepath.Dir(outputPath), os.ModePerm)