Nathan Fisher - The Heisenberg group, sub-Finsler metrics, and the horofunction boundary

Round-16 hunt: picked; source: named-course / course-code long-video search (r16, wave 2); channel screens (sellers/exam/re-upload/devotional/vendor/events), provenance check, vendor/seller/devotional recheck and quality tier A passed; strict per-title check + final strict pass; oEmbed verified.