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

Orchestrators/README-Orchestrators.md

@@ -582,9 +582,9 @@ DAILY_MAINTENANCE_SCRIPTS=(
 
 # host1.conf
 HOST1_DAILY_SYNC_SHARES=(
-    "/mnt/user/Movies"          # HOST1 source of truth — push to HOST2
-    "/mnt/user/Tv_Shows"        # HOST1 source of truth
-    "/mnt/user/Music"           # HOST1 source of truth
+    "/mnt/user/Movies"          # both servers — arr_sync union, rsync spreads files
+    "/mnt/user/Tv_Shows"        # both servers
+    "/mnt/user/Music"           # both servers
     "/mnt/user/Kids_Movies"
     "/mnt/user/Kids_Tv_Shows"
     "/mnt/user/Sports"
@@ -597,8 +597,8 @@ HOST1_PERSONAL_SHARES=(
 
 # host2.conf
 HOST2_DAILY_SYNC_SHARES=(
-    "/mnt/user/Anime_Shows"     # HOST2 source of truth — push to HOST1
-    "/mnt/user/Anime_Movies"    # HOST2 source of truth
+    "/mnt/user/Anime_Shows"     # both servers — arr_sync union, rsync spreads files
+    "/mnt/user/Anime_Movies"    # both servers
 )
 ```