v2 post-migration bug fixes, lidarr_missing_art port, and Partnership SSH/FolderView3 enhancements

Bug fixes across the ecosystem after v1→v2 architecture migration and Unraid 7.2.5 upgrade:

- common.sh: fix _alias_array() phantom empty element (removed [@]:-} pattern), fix
  resolve_remote_ip() with Tailscale FQDN lowercase + awk fallback, add FANART/LASTFM
  key aliases in detect_hosts(), global [@]:-} sweep across 10+ scripts
- webgui_restart.sh: fix emhttp detection (pgrep emhttpd) and restart command for 7.2.5
  (/usr/local/sbin/emhttp stop && start — rc.emhttp removed in 7.2.5)
- bandwidth_monitor.sh, continuous_scripts_status.sh: fix 'local' keyword outside function
- backup_verify.sh: fix resolve_remote_ip() called before detect_hosts()
- Orchestrators: fix script display duplication bug in status output (${entry##*/})
- rsync_stop.sh, git_pull_execute.sh, partnership_manager.sh, coffee_report: lowercase all
  tailscale ip -4 call sites to match Tailscale's lowercase device names
- master_host1.conf: fix SSH key path (gmer4lfe_rsync_automation), add FANART/LASTFM keys
- master_host2.conf: add FANART/LASTFM API keys

New: Media/lidarr_missing_art.sh
- Full ecosystem port of standalone Lidarr artwork fetcher
- Fetches missing album art via fanart.tv + Last.fm APIs
- @tsv batch extraction: 1 jq call per API response vs N*albums (8050 albums in 24s)
- HOST guard (HOST1 only), --status, --dry-run, acquire_lock

New: Initial_run/ssh_setup.sh
- Generates {hostname}_rsync_automation ed25519 keypair (skip if exists, --force to regen)
- ssh-copy-id to remote via Tailscale IP, auto-updates master_host*.conf
- --validate mode: strike tracking (SSH_MAX_STRIKES, SSH_STRIKE_RESET_HRS),
  notify at limit — Tailscale-unreachable remote does NOT count as SSH strike

New: Initial_run/partnership_onboard.sh
- Orchestrator: ssh_setup.sh then partnership_manager.sh --onboard in one command

Partnership/partnership_manager.sh: FolderView3 integration
- Derive partner folder name at runtime (strip unraid- prefix case-insensitively)
- --onboard: create {Mirror}-Failover folder with failover tier containers
- --offboard (both paths): stop + rm containers in folder, remove JSON entry
- --check: calls ssh_setup.sh --validate when IP resolves but SSH state empty
- --status: shows FolderView3 folder state and containers inline

master.conf: SSH_MAX_STRIKES, SSH_STRIKE_RESET_HRS, PARTNERSHIP_FOLDERVIEW3,
PARTNERSHIP_FOLDERVIEW3_URL added to Partnership section

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

master.conf

@@ -178,6 +178,20 @@
     PARTNERSHIP_ONBOARD_NOTIFY=true         # notify both servers on completion
     PARTNERSHIP_SYNC_INTERVAL=15            # minutes — informational, actual schedule in cron
 
+# SSH key lifecycle — managed by Initial_run/ssh_setup.sh.
+# Key named after this server: hostname lowercased, unraid- prefix stripped.
+#   unRAID-Gmer4Lfe → /root/.ssh/gmer4lfe_rsync_automation
+# Run Initial_run/partnership_onboard.sh to generate, copy, and update conf automatically.
+    SSH_MAX_STRIKES=5                       # consecutive SSH auth failures before critical notify
+    SSH_STRIKE_RESET_HRS=24                 # hours since last failure before strike counter resets
+
+# FolderView3 plugin integration — chodeus/VladoPortos/scolcipitato.
+# Creates a "{Partner}-Failover" folder on onboard, removes + cleans containers on offboard.
+# Folder name derived from remote hostname (strip unraid- prefix case-insensitively).
+# Plugin config: /boot/config/plugins/folder.view3/docker.json
+    PARTNERSHIP_FOLDERVIEW3=true            # create/remove FolderView3 folder on onboard/offboard
+    PARTNERSHIP_FOLDERVIEW3_URL=""          # CA plugin URL — leave empty to skip auto-install
+
 # ==============================================================================================
 # ── LOGGING ───────────────────────────────────────────────────────────────────────────────────
 # ==============================================================================================
@@ -835,6 +849,13 @@
         "*.lrc"
     )
 
+# Lidarr artwork fetcher settings
+    LIDARR_ART_MIN_SIZE=10000           # bytes — reject downloads smaller than this
+    LIDARR_ART_MAX_PARALLEL=4           # concurrent background download jobs
+    LIDARR_ART_RETRIES=2                # download retry attempts per image
+    LIDARR_ART_SLEEP_BETWEEN=0.2        # seconds between fanart.tv API calls
+#   HOST*_FANART_API_KEY / HOST*_LASTFM_API_KEY — set in master_host*.conf
+
 # Sonarr shared settings
     SONARR_ORPHAN_AGE=7             # days — files must be older than this before eligible for deletion
     SONARR_MAX_DELETE_GB=10         # require --i-know-what-im-doing if deletion exceeds this