Storage-mode awareness pass + doc update for System_Essentials through Partnership

All state/data file paths in scripts and PHP now resolve via STATE_DIR / DATA_DIR /
PERSISTENT_CONF_CACHE instead of hardcoded /boot/config/ or /tmp/ paths, so the
ecosystem works in both internal and appdata storage modes.

PHP layer (watchdog.php, partnership.php, fallback.php, monitor.php, snapshot.php,
config.php): all state reads switched to STATE_DIR constant; remote state reads use
the new vv_remote_state_cmd() helper which resolves the remote's SCRIPTS_DIR via
their varaverk.cfg before building the path.

conf_sync.sh: fixed SCRIPTS_ROOT → SCRIPTS_DIR bug on MY_CONF path; added
_remote_scripts_dir() to resolve partner's SCRIPTS_DIR before SCP pull.

fallback.php page: added controls card (PARTNERSHIP_ENABLED, FALLBACK_ENABLED,
FALLBACK_RSYNC_ENABLED toggles), status grid, and settings card.

README and Manual updated for System_Essentials, Watchdogs, Fallback, Rsync,
Media, Monitors, Orchestrators, Partnership: added new scripts (conf_sync,
conf_cache_save/restore, conf_cache_watchdog, play_state_sync, start_webhook_listener,
upgrade_webhook_handler), corrected all stale /boot/config/ state file paths to
$STATE_DIR/$DATA_DIR, noted webgui/php_fpm/mover/user_scripts scripts moved to
Plugin/unraid/System_Essentials, fixed start_webhook_listener.sh header (Node.js,
not PHP -S).

Media/Manual-Media.md

@@ -132,8 +132,8 @@ LIDARR_IMPORT_SCAN_TIMEOUT=600   # seconds to wait for pre-flight import scan
 LIDARR_VERSION_MAJOR=3           # expected Lidarr major version (API safety check)
 LIDARR_EXTENSIONS=("flac" "mp3" "m4a" "wav" "aac" "ogg" "opus" "wma")
 LIDARR_PROTECTED_PATTERNS=("*.jpg" "*.jpeg" "*.png" "*.nfo" "*.lrc")
-LIDARR_TRACKED_COUNT_FILE=/boot/config/lidarr_tracked_count  # persistent baseline
-ARR_CLEANUP_STATS=/boot/config/arr_cleanup_stats.db          # read by coffee report
+LIDARR_TRACKED_COUNT_FILE="$DATA_DIR/lidarr_tracked.count"   # persistent baseline
+ARR_CLEANUP_STATS="$DATA_DIR/arr_cleanup_stats.db"           # read by coffee report
 ```
 
 ---
@@ -171,7 +171,7 @@ RADARR_PROTECTED_PATTERNS=("*.jpg" "*.jpeg" "*.png" "*.nfo" "*.srt" "*.sub" "*.a
 
 ```bash
 ARR_SYNC_ENABLED=true
-ARR_SYNC_BLOCKLIST=/boot/config/arr_sync_blocklist.tsv  # tombstone file
+ARR_SYNC_BLOCKLIST="$DATA_DIR/arr_sync_blocklist.tsv"   # tombstone file
 ARR_SYNC_CONNECT_TIMEOUT=10       # SSH connect timeout in seconds
 ARR_SYNC_API_TIMEOUT=60           # curl API call timeout in seconds
 DOCKER_APPDATA_BASE=/mnt/user/appdata
@@ -189,7 +189,7 @@ ARR_IMPORT_RECOVERY_AGE=6        # hours — items newer than this are skipped
 SONARR_VERSION_MAJOR=4
 RADARR_VERSION_MAJOR=6
 LIDARR_VERSION_MAJOR=3
-ARR_RECOVERY_STATS=/boot/config/arr_recovery_stats.db   # read by coffee report
+ARR_RECOVERY_STATS="$DATA_DIR/arr_recovery_stats.db"    # read by coffee report
 ```
 
 ---
@@ -274,6 +274,47 @@ Requires `HOST*_TMDB_API_KEY` in `host*.conf`.
 
 ---
 
+### Play State Sync
+
+```bash
+PLAY_STATE_SYNC_ENABLED=true          # toggle entire sync
+PLAY_STATE_SYNC_LOOKBACK_DAYS=30      # history window for played items
+```
+
+Emby and Jellyfin servers configured per-host:
+
+```bash
+# host*.conf
+HOST1_EMBY_URL="http://192.168.50.2:8096"
+HOST1_EMBY_API_KEY="..."
+HOST1_JELLYFIN_URL=""   # empty = skip Jellyfin on this host
+HOST1_JELLYFIN_API_KEY=""
+```
+
+---
+
+### Upgrade Webhook
+
+```bash
+# master.conf
+WEBHOOK_PORT=9456                     # 0 = disable listener
+WEBHOOK_SECRET=""                     # auto-generated on first start if empty
+WEBHOOK_UPGRADE_RSYNC_ENABLED=true    # push upgraded file to remote nodes
+```
+
+```bash
+# host*.conf
+HOST1_WEBHOOK_LAN_IP="192.168.50.2"  # IP arrs call for webhook delivery
+```
+
+When `WEBHOOK_PORT=0`, `start_webhook_listener.sh` exits cleanly and no listener starts.
+When `WEBHOOK_SECRET` is empty, a 32-byte hex secret is generated on first start and
+written back to `master.conf`. Run `Tools/webhook_setup.sh` to register the URL in arrs.
+
+Webhook log: `/var/log/varaverk/upgrade_webhook.log`
+
+---
+
 ### Orchestrator Job Order
 
 ```bash