update stale media ownership language across all docs

arr_sync.sh bidirectional union replaced the old split-ownership model.
Old: HOST1 owns Movies/TV/Music, HOST2 owns Anime — each arr manages
different shares to avoid conflicts.
New: arr_sync.sh keeps all arr databases in union. Either server can
download to any share at any time. The union is the source of truth.

Auth stack references left intact — HOST1 still owns auth config
(one-way sync to HOST2). Only media library ownership language updated.

Files changed:
  README.md                          — server block + share annotations
  Fallback/README-Fallback.md        — role line + Split Source of Truth section
  Orchestrators/README-Orchestrators — daily sync share comments
  Rsync/Manual-Rsync.md              — DEFAULT_RSYNC_OPTS comment block
  Media/README-Media.md              — HOST AWARENESS section

README.md

@@ -24,15 +24,15 @@ HOST1 — unRAID-Gmer4Lfe
   Hardware:  Threadripper 1950X, 128GB RAM, ZFS cache pools
   Location:  Primary site
   Domain:    Gmer4Lfe.com
-  Owns:      Movies, Tv_Shows, Music — source of truth
-             Auth stack — source of truth
+  Arrs:      Movies, Tv_Shows, Music — union with HOST2 via arr_sync
+             Auth stack — source of truth (HOST1 owned, syncs to HOST2)
              Emby — primary media server
 
 HOST2 — unRAID-Jayred365
   Hardware:  Intel i5 10th gen, 64GB RAM
   Location:  Remote — different building, different power utility
   Domain:    Gmer4Lfe.us
-  Owns:      Anime_Shows, Anime_Movies — source of truth
+  Arrs:      Anime_Shows, Anime_Movies — union with HOST1 via arr_sync
              His own Emby — for his household
 ```