feat: slskd reconnect guard in downloaders_reset, mass v2 sync

- downloaders_reset: connection check block before slskd API sections;
  triggers PUT /api/v0/server reconnect if disconnected, polls 60s,
  gates Stuck Searches and Dead Transfer Records on SLSKD_CONNECTED
- Sync all modified/new/deleted files from v2 refactor across Docker_Essentials,
  Media, Monitors, Partnership, Rsync, Tools, Transcodes, unRAID_Essentials,
  common.sh, master confs, and new Manual/README docs

Monitors/system_tuning_monitor.sh

@@ -2,58 +2,101 @@
 # ==============================================================================================
 # ============================= System Tuning Monitor ==========================================
 # ==============================================================================================
-# Tracks inotify and php-fpm usage over time.
-# Snapshots written every 6 hours — read by sunday_morning_coffee_report.sh for weekly summary.
-# Schedule: 0 */6 * * * (every 6 hours via User Scripts)
 #
-# ── WHAT IT TRACKS ────────────────────────────────────────────────────────────────────────────
-#   inotify instances:
-#     Current in use vs kernel limit
-#     % utilization — warns above INOTIFY_WARN_PCT (default 80%)
-#     Top 5 consumers by instance count
-#     Symptom of exhaustion: containers miss file events, downloads not detected,
-#     Live TV stutter, library not updated
+# PURPOSE
+# ─────────────────────────────────────────────────────────────────────────────
+# inotify and PHP-FPM utilisation tracking via time-series snapshots. Scheduled
+# every 6 hours (0 */6 * * *). Writes one bounded log entry per run to
+# TUNING_MONITOR_LOG. weekly_health_digest.sh reads this log to report peak,
+# average, and warning counts over the week.
 #
-#   php-fpm workers:
-#     Active workers vs PHP_MAX_CHILDREN limit
-#     % utilization — warns above PHP_FPM_WARN_PCT (default 80%)
-#     Symptom: unRAID WebGUI slowdowns or timeouts under load
+# Background snapshot script — no output when healthy. Warns (and notifies) only
+# when INOTIFY_WARN_PCT or PHP_FPM_WARN_PCT thresholds are exceeded.
 #
-# ── LOG FORMAT ────────────────────────────────────────────────────────────────────────────────
-#   DATE|TIME|INOTIFY_USED|INOTIFY_LIMIT|INOTIFY_PCT|INOTIFY_WARN|PHPFPM_ACTIVE|PHPFPM_MAX|PHPFPM_PCT|PHPFPM_WARN
-#   Log trimmed to TUNING_LOG_RETENTION days on each write — bounded size.
+# inotify exhaustion symptoms: downloads complete but arrs don't detect them,
+# live TV stutter, library updates stop. PHP-FPM exhaustion symptoms: unRAID
+# WebGUI slowdowns or timeouts under load.
 #
-# ── WHAT THE WEEKLY REPORT SHOWS ──────────────────────────────────────────────────────────────
-#   inotify: peak, average, warning count over the week
-#   php-fpm: peak workers, average workers, warning count over the week
+# ==============================================================================================
+# OPERATIONAL MODEL
+# ==============================================================================================
 #
-# ── SILENT BY DEFAULT ─────────────────────────────────────────────────────────────────────────
-# Background snapshot script — no output when healthy.
-# Warns to stderr when thresholds exceeded — visible in User Scripts output log.
-# Does NOT notify on every snapshot — only when threshold exceeded.
+# Each run snapshots:
+#   inotify: instances in use vs INOTIFY_MAX_INSTANCES kernel limit.
+#            Top 5 consumers by instance count. Warns above INOTIFY_WARN_PCT.
+#   php-fpm: active workers vs PHP_MAX_CHILDREN limit.
+#            Warns above PHP_FPM_WARN_PCT.
 #
-# ── HOST AWARENESS ────────────────────────────────────────────────────────────────────────────
-# Each server writes to its own DATA_DIR — no collision between servers.
-# MY_ID included in warning output for clarity in shared notification channels.
+# Log line format (one per run, trimmed to TUNING_LOG_RETENTION days):
+#   DATE|TIME|INOTIFY_USED|INOTIFY_LIMIT|INOTIFY_PCT|INOTIFY_WARN|
+#   PHPFPM_ACTIVE|PHPFPM_MAX|PHPFPM_PCT|PHPFPM_WARN
+# INOTIFY_WARN and PHPFPM_WARN are 1/0 flags. weekly_health_digest.sh counts
+# warnings over the week to show trend severity.
 #
-# ── SAFEGUARDS ────────────────────────────────────────────────────────────────────────────────
-#   acquire_lock     — prevents overlapping 6-hour snapshots
-#   root check       — /proc/*/fd requires root access
-#   atomic log write — tmp file + mv prevents partial writes on trim
-#   validate_unraid  — notify script validated before use
+# ==============================================================================================
+# OPERATIONAL SAFEGUARDS
+# ==============================================================================================
 #
-# ── CONFIGURATION (master.conf) ───────────────────────────────────────────────────────────────
-#   INOTIFY_WARN_PCT      — warn threshold % (default 80)
-#   PHP_FPM_WARN_PCT      — warn threshold % (default 80)
-#   PHP_MAX_CHILDREN      — max php-fpm workers (set by php_fpm_max_children.sh)
-#   TUNING_MONITOR_LOG    — log file path
-#   TUNING_LOG_RETENTION  — days before old entries purged (default 30)
+# Single Instance Lock
+#   acquire_lock prevents overlapping 6-hour snapshot runs.
+#
+# Root Enforcement
+#   /proc/*/fd enumeration for inotify consumer counting requires root access.
+#
+# Atomic Log Write
+#   Trim uses tmp file + mv — partial writes during log rotation cannot corrupt
+#   the accumulated history.
+#
+# Notification Validated
+#   validate_unraid_cmd confirms the notify script is present before use.
+#
+# ==============================================================================================
+# STATE FILES
+# ==============================================================================================
+#
+#   TUNING_MONITOR_LOG   — DATA_DIR/tuning_monitor.db
+#       One line per 6-hour snapshot. Trimmed to TUNING_LOG_RETENTION days on
+#       each write — bounded size. Read by weekly_health_digest.sh for trend
+#       reporting. Resets if DATA_DIR is cleared.
+#
+# ==============================================================================================
+# CONFIGURATION
+# ==============================================================================================
+#
+# master.conf
+#
+#   INOTIFY_WARN_PCT
+#       Warn if inotify instances exceed this percentage of the kernel limit. (default: 80)
+#
+#   PHP_FPM_WARN_PCT
+#       Warn if php-fpm active workers exceed this percentage of PHP_MAX_CHILDREN. (default: 80)
+#
+#   PHP_MAX_CHILDREN
+#       Maximum php-fpm workers — set by php_fpm_max_children.sh in unRAID_Essentials.
+#
+#   TUNING_MONITOR_LOG
+#       Log file path. (default: DATA_DIR/tuning_monitor.db)
+#
+#   TUNING_LOG_RETENTION
+#       Days before old entries are purged. (default: 30)
+#
+# ==============================================================================================
+# RUNTIME MODES
+# ==============================================================================================
+#
+# system_tuning_monitor.sh
+#     Take snapshot. Write to log. Warn (and notify) if thresholds exceeded.
+#     Silent when healthy.
+#
+# system_tuning_monitor.sh --dry-run
+#     Measure inotify and PHP-FPM utilisation and display results. No log write.
+#
+# system_tuning_monitor.sh --status
+#     Show thresholds, log path, and retention. Then exit.
+#
+# system_tuning_monitor.sh --log
+#     Verbose output during the snapshot including top inotify consumers.
 #
-# ── USAGE ─────────────────────────────────────────────────────────────────────────────────────
-#   system_tuning_monitor.sh              — normal snapshot run
-#   system_tuning_monitor.sh --dry-run    — measure and show, no log write
-#   system_tuning_monitor.sh --log        — verbose output
-#   system_tuning_monitor.sh --status     — show config and exit
 # ==============================================================================================
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"