READY page: LED CROSS checks the Resolume columns Sunday's slides call up

- For every item in the plan's ProPresenter playlist: the macros its slides fire (read on the
  ProP Mac from Configuration/Macros and the .pro files), the RossTalk "CC page/row/col" each
  macro sends to Companion, the Companion buttons that one presses in turn, down to Resolume's
  /composition/columns/N/connect. Each such column must hold a clip on some layer (one whose
  ignore-column-trigger is not On), and Resolume must be on the Service deck.
- COL N EMPTY / COL N MISSING name the column and the items that use it. The hold only puts
  Resolume back on its deck; it never plays a clip. "Something is playing" is no longer checked.
- ready.prop_host replaces ready.led_clip.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

settings/ui/app.js

@@ -569,7 +569,7 @@
     prop: "The ProPresenter playlist for the plan's date has every Planning Center item; MC announcements have a slide each and this week's notes; every person listed for baptisms or dedications has a slide.",
     timecode: "Every song's presentation has a timeline, and Planning Center's LTC note for every song is the timecode the tracks play at that song's start.",
     backgrounds: "Every song has at least one slide with a background.",
-    led_cross: "Resolume is on the Service deck and a clip is playing on the cross.",
+    led_cross: "Every Resolume column Sunday's slides call up (slide → macro → Companion → column) holds content, and Resolume is on the Service deck.",
     lineup: "The Band Lineup TV shows this plan, nobody who is not on it or declined, and everyone on the band and communication teams.",
     track_bundle: "Every location has this weekend's Ableton project folder on the shared drive.",
     prop_bundle: "A ProPresenter bundle was saved for the locations since Monday.",