v0.13.6

Fixed

• A <script src> in an EPUB 2 book loads its target, and ADV-010 did not
  know it. Doitsu, MobileRead 374286 #284: a book whose ch1.xhtml carries
  <script src="../js/util.js"> and two more drew three advisories saying
  nothing draws, applies or loads those files.

  One continue was serving two questions. epubcheck's EPUB 2 handler
  registers no reference for an HTML <script src> — a missing target draws no
  RSC-007 there — and we skip that existence check to match; the skip took
  the reference registration with it. But "does any document load this file"
  is ADV-010's question, and epubcheck does not ask it of an EPUB 2 book at
  all, so there was no parity to preserve by staying silent, only a false
  positive to make. The reference is now registered and the existence check is
  still skipped, with a test pinning both halves.

  Probing the rest of the class rather than only the reported shape: fourteen
  reference spellings in one EPUB 2 book — img@src, object@data,
  video@poster, audio/source/track/embed/iframe/input@src,
  link rel=stylesheet, a CSS url(), MathML altimg and an SVG
  image@xlink:href — and <script src> was the only one missing.

  Nothing here could have found it, and that is measured rather than assumed:
  the 981-scenario corpus is unchanged (100% exact-ID recall, 0 false
  positives), the reference shelf is unchanged to the finding (212 ADV-010
  across 100 books, identical in both builds), and the reason is that of its
  474 books only 6 carry a <script src> at all, and none of the 390 EPUB 2
  ones does. Without the flag the two tools already agreed exactly on
  Doitsu's book — both silent.

Full notes: CHANGELOG.md. Also on crates.io.