merge: bring Horseshoe Las Vegas booking from gh/master

Resolve against the bookings/{stays,transport} layout, couple payer
names, and the days/ timeline: move hotel-vegas-horseshoe.md into
bookings/stays/, swap the Wyndham ledger row for Horseshoe US$1,067.70
(KTVT, shared 50/50; settlement now US$715.37), and point Sep 30–Oct 3
day files at the Horseshoe.

Claude-Session: https://claude.ai/code/session_01SQPbfX7jyTALGYxJw36hbT

days/2026-10-03.md

@@ -4,6 +4,6 @@
 
 ## Logistics
 
-- Check out of Wyndham by 10 AM
+- Check out of Horseshoe by 11 AM
 - KT & VT fly LAS → Sofia ([flights](../bookings/transport/flights-kt-vt.md))
 - MS starts the drive back to SF