feat(twitter_threads): gallery-dl media download + inline media embeds in Markdown

download_media now shells out to gallery-dl (handles X.com auth/403/video->mp4) instead of urllib, returns the downloaded files, + media_files_for_post glob helper + --cookies CLI. render_markdown embeds images with ![](...) and videos with an HTML <video controls> tag (were plain links). extract_corpus uses the package download_media (one download path). Tests rewritten for the gallery-dl API. Corpus: 4 threads, 33 media (32 img embeds + 1 video), 0 missing.

conductor/tracks/twitter_threads_extraction_20260705/extract_corpus.py

@@ -18,7 +18,6 @@ from __future__ import annotations
 
 import json
 import shutil
-import subprocess
 import sys
 from pathlib import Path
 
@@ -26,6 +25,7 @@ sys.path.insert(0, str(Path(__file__).resolve().parents[3]))
 
 from scripts.twitter_threads.error_types import ThreadData
 from scripts.twitter_threads.fetch_thread import fetch_thread_from_url, thread_to_dict
+from scripts.twitter_threads.download_media import download_media, media_files_for_post
 from scripts.twitter_threads.render_markdown import render_markdown
 
 TRACK = Path(__file__).resolve().parent
@@ -62,12 +62,6 @@ def ensure_cookies() -> None:
  COOKIES_NS.write_text("\n".join(out) + "\n", encoding="utf-8")
 
 
-def gdl_download(url: str, media_dir: Path) -> None:
- media_dir.mkdir(parents=True, exist_ok=True)
- subprocess.run(
-  ["gallery-dl", "--cookies", str(COOKIES_NS), "-o", "text-tweets=true", "-o", "conversations=true", "-D", str(media_dir), url],
-  capture_output=True, text=True,
- )
 
 
 def groups(items: dict[str, dict]) -> list[list[str]]:
@@ -116,9 +110,10 @@ def main() -> int:
   td = ThreadData(root_post_id=primary, posts=tuple(union), source_url=items[primary]["url"])
   base = CORPUS / primary
   media_dir = base / "media"
+  media_dir.mkdir(parents=True, exist_ok=True)
   for m in members:
-   gdl_download(items[m]["url"], media_dir)
-  media_names = {p.post_id: sorted(f.name for f in media_dir.glob(f"{p.post_id}_*")) for p in td.posts}
+   download_media(items[m]["td"], media_dir, COOKIES_NS)
+  media_names = {p.post_id: media_files_for_post(media_dir, p.post_id) for p in td.posts}
   media_names = {k: v for k, v in media_names.items() if v}
   n_media = sum(len(v) for v in media_names.values())
   data = thread_to_dict(td)