The crawler took one hardcoded novel URL, wrote per-chapter text files
into ./data, and fetched serially until the site answered 429.
Rename the module to hako-crawler and split fetching, page parsing and
crawl orchestration into a hako package that takes any novel URL.
The chapter body is no longer served as markup: #chapter-content now
carries a shuffled, XOR-obfuscated payload that the site's own script
expands in the browser, so the previous p[id=<digits>] extractor
returned nothing at all. Decode it, keeping the plain-markup path as a
fallback. The scheme is read from the page and an unrecognised one is a
hard error, because the alternative is exporting a book of mojibake.
Space requests globally instead of per-goroutine, so concurrency no
longer raises the request rate, and retry only what a retry can fix.
Cache raw pages so re-runs cost no requests.
BREAKING CHANGE: module path is now github.com/tiennm99/hako-crawler,
and the novel URL is a required argument rather than a constant.
tiennm99