overpass.kumi.systems has higher rate limits than overpass-api.de.
This is the same endpoint brouter-web uses as its default.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Overpass API sometimes returns HTTP 200 with a plain-text error body
containing "rate_limited" instead of a proper 429 status. Now checks
response body for this pattern before attempting JSON parse.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>