chore: move the archive-fetching tooling out of this branch

The fetching scripts and their docs now live on the `tooling` branch, which
is not published to GitHub. This removes the two references that would
otherwise dangle here: the `jd2` npm script and the CLAUDE.md bullet
describing it.

The viewer's own gallery-dl support is untouched and stays here —
src/lib/gallery-dl-sidecar.ts and friends parse sidecars at display time and
are app code, not tooling.

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

CLAUDE.md

@@ -15,9 +15,6 @@ 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`)
 
 Local development usually needs both `npm run dev` and `npm run server`. Local-folder mode works without the backend; server-mode archives do not.