* feat(web,download): absorb #1048 media + --stdout into web read
Distill the useful pieces of the abandoned PR #1048 (`web md`) into the
existing shared pipeline instead of introducing a parallel command:
- Turndown rules for <video> / <audio> / <iframe>. Video and audio are
emitted as inline HTML so renderers that support it keep playback,
and iframes degrade to markdown links (title + src) so embedded
content (YouTube, CodePen, …) stays reachable. `iframe` moves out of
STRIPPED_TAGS since it's now handled explicitly.
- `stdout` option on ArticleDownloadOptions: writes the full markdown
to process.stdout, skips image download + mkdir + file write, and
reports saved='-'. Remote image URLs stay intact so piped output is
self-contained.
- `web read --stdout` wires the above through.
- Lazy-load src rewrite: the extractor now promotes data-src /
data-original / data-lazy-src / data-srcset onto `src` before the
HTML is frozen, so the markdown body and the image-download list
reference the same URL (previously a page with placeholder.gif +
data-src produced broken image links in the output).
Nothing in #1048 that overlapped with the already-merged #1143
hardening was kept — no new Readability wiring, no duplicate Turndown
config, no new command.
* fix(web): keep stdout streaming output clean
* fix(tests): update iframe e2e assertion and drop relative src import
- article-extract e2e fixture test: iframe now converts to a markdown
link instead of being stripped, so assert the YouTube embed link
survives rather than asserting its absence.
- clis/web/read.test.js: replace vi.importActual('../../src/registry.js')
with a direct __test__.command export from read.js; the relative
import into src/ tripped the package-exports adapter guardrail.
jakevin