fuel-prices: restore New Zealand (MBIE) — source moved behind Incapsula JS bot-wall

[koala73]

Problem

scripts/seed-fuel-prices.mjs fetchNewZealand() can no longer retrieve the MBIE weekly fuel CSV. Around 2026-05-20, mbie.govt.nz moved its entire domain (apex, the weekly-fuel-price-monitoring data page, and the weekly-table.csv asset) behind an Incapsula (Imperva) JS bot-challenge. The URL now returns:

• HTTP 200, content-type: text/html, ~212 bytes
• body is an _Incapsula_Resource challenge stub, not CSV

Verified blocked from all of: a residential IP, a datacenter IP, and the Decodo residential proxy. data.govt.nz and figure.nz mirrors are also Incapsula-walled. A plain fetch/curl cannot pass a JS challenge from any IP.

Interim mitigation (shipped in PR #4007)

'New Zealand' added to TOLERATED_FAILURES so the dead source no longer rejects the whole validated fuel-prices publish (same precedent as Brazil). fetchNewZealand() still runs every cycle and NZ is carried automatically the moment the source returns CSV again — so if this is fixed, no code change to the validator is needed.

To actually restore NZ (pick one)

1. Headless / challenge-solver fetch — integrate FlareSolverr / browserless / a Zyte/ScrapingBee unblocker for fetchNewZealand() (reusable for any future JS-walled source). New infra + dependency + cost.
2. Alternative source — find a non-walled host that publishes the same MBIE weekly board prices (e.g. an official API, a data.govt.nz CKAN resource that serves the raw CSV without the wall, or another aggregator).
3. Accept NZ as permanently best-effort like Brazil and close this (data stays absent).

Acceptance

• fetchNewZealand() returns NZ gasoline + diesel in NZD/L again, and
• once NZ is reliably present, optionally remove it from TOLERATED_FAILURES to re-tighten the gate.

Context: WM 2026-06-01 DEGRADED triage. See scripts/seed-fuel-prices.mjs TOLERATED_FAILURES comment + fetchNewZealand() (~line 499).