rename appdata-Failover→appdata-Fallback in docs; critical sync 15→30min; transcode 3→7min

appdata-Failover → appdata-Fallback:
  All .md files updated — scripts and confs already used appdata-Fallback.
  Share was renamed; docs were the only stale references.

critical_sync_maintenance.sh: */15 → */30, 96/day → 48/day:
  critical_sync_maintenance.sh header, master.conf, host1/2.conf comments,
  Orchestrators README, User Script Plug-in README, Partnership README/manual/script,
  Docker_Essentials README/downloaders_reset.sh, Fallback README,
  weekly_sync_maintenance.sh, user_script_plug-in.sh all updated.

rsync_emby_failover User Script superseded:
  Emby dirty sync was already in HOST1_CRITICAL_SYNC_SHARES — it now runs inside
  critical_sync_maintenance.sh every 30min alongside auth sync and partnership check.
  Section in User Script Plug-in README marked for deletion from plugin.

transcode_management.sh: */3 → */7:
  transcode_management.sh, transcode_manager.sh, transcode_cleanup.sh headers,
  Transcodes README/manual, Orchestrators README, User Script Plug-in README,
  user_script_plug-in.sh all updated.

README.md

@@ -243,14 +243,14 @@ where determines whether you need encryption and whether sync failure matters.
 # services to work correctly when they start on HOST2.
 #
     /mnt/user/Media_Server/Emby              # Emby userdata — watch history, playstates
-    /mnt/user/appdata-Failover/Critical-Data # auth stack — NPM rules, certs, user accounts
+    /mnt/user/appdata-Fallback/Critical-Data # auth stack — NPM rules, certs, user accounts
     /mnt/user/Movies                         # media library content
     /mnt/user/Tv_Shows                       # media library content
     /mnt/user/Music                          # media library content
 #
 # Sync failure here = failover runs but with stale data (acceptable) or missing
 # data (problematic). These sync every night via daily_sync_maintenance.sh.
-# Critical-Data and Emby also sync every 15 minutes via critical_sync_maintenance.sh.
+# Critical-Data and Emby also sync every 30 minutes via critical_sync_maintenance.sh.
 # ─────────────────────────────────────────────────────────────────────────────
 ```
 
@@ -266,8 +266,8 @@ where determines whether you need encryption and whether sync failure matters.
 # Content is not sensitive — anyone with access to HOST2 could read it.
 #
 # Examples:
-    /mnt/user/appdata-Failover/Gmer4Lfe      # Gmer4Lfe server appdata backup
-    /mnt/user/appdata-Failover/Important-Data # NextCloud, Immich appdata
+    /mnt/user/appdata-Fallback/Gmer4Lfe      # Gmer4Lfe server appdata backup
+    /mnt/user/appdata-Fallback/Important-Data # NextCloud, Immich appdata
     /mnt/user/Kids_Movies                    # kids content — not sensitive
     /mnt/user/Sports                         # sports content — not sensitive
 #
@@ -345,7 +345,7 @@ This is not standby. This is mutual coverage between peers.
 #
 # "Minimal disruption" does NOT mean:
 #   Zero downtime (DDNS TTL = 1 minute, brief gap expected)
-#   Perfect consistency (Emby userdata is 15min stale at most)
+#   Perfect consistency (Emby userdata is 30min stale at most)
 #   All services covered immediately (tiered start over 24 hours)
 #
 # The system is designed around the real experience of a household:
@@ -363,7 +363,7 @@ This is not standby. This is mutual coverage between peers.
 ```bash
 # ─────────────────────────────────────────────────────────────────────────────
 # Things conventional failover provides that this does NOT:
-#   Zero RPO (recovery point objective) — there is ~15min of potential staleness
+#   Zero RPO (recovery point objective) — there is ~30min of potential staleness
 #   Synchronous state replication — changes don't reach HOST2 instantly
 #   Automatic failure detection in seconds — fallback.sh checks every 2 minutes
 #   Transparent IP migration — DNS TTL means up to 1 minute of routing to old IP
@@ -426,7 +426,7 @@ server's own domain.
 #
 # HOST1 is source of truth for the auth configuration. All changes to NPM proxy
 # rules, LLDAP users, Authelia policies, and certs happen on HOST1 and propagate
-# to HOST2 via Critical-Data sync every 15 minutes.
+# to HOST2 via Critical-Data sync every 30 minutes.
 #
 # HOST2 operator's experience: click NginxProxyManager in Docker UI →
 # browser opens HOST1's NPM via Tailscale redirect → make changes there →
@@ -451,7 +451,7 @@ Always running:
 Source of truth:
   Media           Movies, Tv_Shows, Music  ←──  Anime_Movies, Anime_Shows
                   ───────────────────────→       (bidirectional daily push)
-  Config          auth stack config        ──→   mirrored every 15 min
+  Config          auth stack config        ──→   mirrored every 30 min
   Emby state      watch history, playstates──→   dirty sync every 30 min
 
 Failover coverage:
@@ -621,7 +621,7 @@ Throughout the day (every minute via watchdog_orchestrator.sh):
 Throughout the day:
   fallback.sh                 watching: remote server, internet connectivity
   transcode_management.sh     managing: ramdisk ↔ SSD, session cleanup (every 3min)
-  critical_sync_maintenance.sh keeping: auth stack + Emby current (every 15min)
+  critical_sync_maintenance.sh keeping: auth stack + Emby current (every 30min)
 
 1am:
   git pull (latest scripts first)