Splits the nebulous gandi-operations how-to into two single-topic cards
(manage-eblu-me-dns, rotate-gandi-pat) and adds a mise task for the
recurring _acme-challenge TXT cleanup needed due to a value-comparison
bug in libdns/gandi v1.1.0 that prevents certmagic's cleanup phase from
removing presented TXT values.
The gandi reference card is updated to drop the false "different
credential from Pulumi PAT" claim — verified during the 2026-04-27
incident that Caddy and Pulumi share a single PAT.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>