[PIPELINE] Add --force-cache mode and local dev Makefile

[wi287g]

Prevent hammering ICE/ACLU servers during local development.

Tasks

• Verify python scripts/fetch_287g.py --force-cache works end-to-end (html already saved by first run)
• Add a Makefile (or scripts/run_pipeline.sh) with:
  • make fetch — live fetch, save cache
  • make local — --force-cache only (fast, no network)
  • make merge — run merge step
  • make all — full pipeline
• Document in README under "Running the pipeline locally"