v0.6.0

Added

• Exoplanet.Sanitizer behaviour: optionally delegate HTML sanitization to a
  comprehensive library (e.g. html_sanitize_ex) via
  config :exoplanet, sanitizer_adapter: MyAdapter. When set, the adapter
  replaces the built-in sanitizer.
• CONTRIBUTING.md with development setup, test conventions, and the
  DateTimeParser regeneration workflow.

Changed

• feed_timeout is now enforced at the HTTP layer as Req's
  :receive_timeout (it previously only bounded the surrounding task), and
  Req's automatic retries are now disabled by default — a retried request
  could never finish inside the task backstop anyway, and a prompt error
  return is what enables the cached-body fallback. Re-enable retries via
  :req_options if you need them.
• Exoplanet.Config.from_file/1 and Exoplanet.build/1 now share one
  canonical defaults-merge path (Exoplanet.Filters.merge/2); nil values
  in default_filters keep the library default in both entry points.
• Exoplanet.DateTimeParser.parse/1 now always returns
  {:ok, NaiveDateTime.t()} or a two-element {:error, reason} tuple
  (it previously leaked NimbleParsec's six-element error tuple).

Deprecated

• The application env key for extra Req options is now :req_options.
  The old :planet_req_options key keeps working as a deprecated fallback
  and logs a one-time deprecation warning — rename it to :req_options
  (config :exoplanet, req_options: [...]).

Fixed

• A single slow feed no longer crashes the entire build. Exoplanet.build/1
  now kills tasks that exceed feed_timeout (plus a 1s grace period) and
  drops only that feed, logging a warning that names the feed URL.
• Exoplanet.DateTimeParser no longer corrupts pre-2000 RFC 822 dates.
  Four-digit years pass through unchanged (1999 used to become 3999), and
  two-digit years follow the RFC 2822 century rule: 00-49 → 2000s, 50-99 →
  1900s ("99" used to become 2099).
• Exoplanet.Parser now ensures the cache adapter module is loaded before
  probing for the optional on_success/on_error callbacks, so they are no
  longer silently skipped in interactive/dev environments.
• RSS/Atom detection now inspects only the feed's root element instead of
  scanning the whole body for <rss/<rdf:RDF. An Atom feed that merely
  mentions those strings inside an entry's content is no longer misparsed
  as RSS.

Security

• The default HTML sanitizer (sanitize_html: true) now also removes on*
  event-handler attributes and URL-bearing attributes (href, src,
  srcset, action, formaction, poster, xlink:href) whose URL
  scheme is not http, https, or mailto (relative URLs are kept).
  Previously javascript: links and inline event handlers passed through.
• The default drop_tags now also drops the SVG SMIL animation elements
  animate, set, animateTransform, and animateMotion. These can
  animate an ancestor <a>'s href to a javascript: URL via their
  to/values/from/by attributes — attribute names the URL-scheme
  allowlist does not cover — so the payload previously survived
  sanitization. Inline <svg> images are unaffected. Configs that set
  drop_tags explicitly should add these four element names.