Update quotes (one command)

Run the price update of UPDATE_PRICES.md end to end, then give the user a short report. Work from the repository root.
Use python (Windows) or python3 where python is missing. Read-only Scalable tools only; never edit data files by hand.

1. Plan: python data/update_prices.py --plan
   • WARNING: … more than three_months covers → stop and ask the user how to proceed.
   • Otherwise it prints one prompt per batch (--- prompt 1/2 --- …). Do not print them to the user.
2. Fetch: start one agent per printed prompt, all in one message (agent type price-fetcher, model claude-sonnet-5-5),
   each prompt copied exactly. Wait for all answers. The hook .claude/hooks/save-chart.cjs writes the files; each agent
   only answers SAVED n of m plus any problem lines.
   • Any answer HOOK NOT ACTIVE → stop. Tell the user the quote-saving hook did not run: Node must be installed and on
     PATH, and Claude Code must be restarted once after .claude/settings.json was added (/hooks lists it).
     Never fall back to copying prices by hand.
3. Merge: python data/update_prices.py --finish
   • FETCH AGAIN … → start the printed prompts the same way, then --finish again (at most 2 rounds per ISIN, then show
     the reason lines to the user).
   • STOP: … or CHECK WITH USER: … → show those lines to the user and change nothing else.
4. Report in the user's language, 2–4 lines: the == REPORT == lines (last price date, 30-min / 2-h coverage,
   tests), anything that needs the user, and "reload the dashboard (Ctrl+F5)". Skip note: lines and known warnings.
   Do not commit unless the user asks.