feat: keep the archive-fetching tooling on a branch of its own

The scripts and docs for fetching from Instagram now live here rather than on
main, which is the branch published to GitHub. They carry things that do not
belong in a public repo: the fetch host's public IP, the browser profile path
the cookie is read from, the NAS archive path, and the list of accounts being
archived.

This branch is a superset of main — the viewer plus the tooling — so it can
take main's changes by merging, and the npm script and CLAUDE.md entries that
reference the tooling live here where the files actually exist.

Restored with the sync work from the 2026-08-20 run already in place: the
--abort flag, the corrected yt-dlp install advice, and the measurements behind
both.

Note that main's history was rewritten to strip these paths, so the tooling's
own per-file history does not exist on this branch. It is preserved on gitea
as pre-rewrite-20260820 and pre-rewrite-tooling-20260820.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UXfdJu7QhSJLr47K7koTDF

CLAUDE.md

@@ -15,6 +15,14 @@ InstaArchive Viewer is a React 19 + Vite 6 PWA for browsing archived Instagram d
 - `npm run lint` — type-check only (`tsc --noEmit`)
 - `npm test` / `npm run test:watch` — vitest
 - `npx vitest run src/lib/archive-patterns.test.ts` — a single test file
+- `npm run jd2 -- --archives <dir> --dry-run` — generate JDownloader `.crawljob`
+  files for every profile on disk (see `scripts/jd2-sync.ts` and
+  `docs/jdownloader.md`)
+- `scripts/gdl-sync.py` — the gallery-dl fetcher that replaced JD2 for the
+  ARTMS profiles (see `docs/gallery-dl.md`)
+
+**This branch is not published to GitHub.** `main` is; keep fetching tooling,
+host details and account lists on this branch only.
 
 Local development usually needs both `npm run dev` and `npm run server`. Local-folder mode works without the backend; server-mode archives do not.