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

unRAID_Essentials/inotify_tuning.sh

@@ -2,65 +2,87 @@
 # ==============================================================================================
 # ================================= inotify Tuning ============================================
 # ==============================================================================================
-# Raises Linux inotify limits at array start to prevent exhaustion across the container stack.
-# Run once at array start via ARRAY_START_SCRIPTS in master.conf.
-# Settings are lost on reboot — this script reapplies them on every array start.
 #
-# ── THREE INOTIFY LIMITS ──────────────────────────────────────────────────────────────────────
-#   max_user_instances  — max number of independent inotify file descriptor objects per user
-#                         Each container that calls inotify_init() consumes one instance
-#                         Default 128 — exhausted quickly with 20+ active containers
+# PURPOSE
+# ─────────────────────────────────────────────────────────────────────────────
+# Raises Linux inotify limits at array start to prevent exhaustion across the
+# container stack. Run once at array start via ARRAY_START_SCRIPTS. Settings
+# are lost on reboot — this script reapplies them on every array start.
 #
-#   max_user_watches    — SHARED budget across ALL users and containers on the system
-#                         Each watched file or directory costs one watch from this pool
-#                         Default 8192 — VSCode alone can need 50K-200K for large workspaces
+# Must run FIRST in ARRAY_START_SCRIPTS before any containers start — containers
+# inherit inotify limits at launch, not dynamically. Running this after Code-Server
+# starts requires a docker restart to pick up the new values.
 #
-#   max_queued_events   — max events buffered before kernel starts dropping them
-#                         Low value = events silently lost during high-activity periods
-#                         Default 16384 — sufficient for most setups
+# ==============================================================================================
+# DESIGN PRINCIPLES
+# ==============================================================================================
 #
-# ── WHY VSCODE THROWS "UNABLE TO WATCH FOR FILE CHANGES" ─────────────────────────────────────
-# VSCode (and Code-Server in Docker) opens one inotify watch per file in the workspace.
-# A typical project with node_modules can easily have 100K-200K files.
-# All containers on the host share max_user_watches — the combined usage of:
-#   Sonarr, Radarr, Lidarr, Emby, Nextcloud, Code-Server, AdGuard, all other arrs
-#   easily exceeds 524288 (512K) watches on a busy server.
-# Raising to 1048576 (1M) gives sufficient headroom — safe on 128GB RAM (~128MB kernel use).
+# Three inotify Limits
+#   max_user_instances  — max independent inotify fd objects per user; each container
+#                         calling inotify_init() consumes one. Default 128 — exhausted
+#                         quickly with 20+ active containers.
 #
-# ── STARTUP ORDER MATTERS ─────────────────────────────────────────────────────────────────────
-# inotify_tuning.sh must run BEFORE containers that watch files start.
-# In ARRAY_START_SCRIPTS order: inotify_tuning.sh first, then container-starting scripts.
-# If Code-Server starts before limits are raised it inherits the old (low) limits.
-# Code-Server restart fixes this: limits are kernel-wide, not process-bound at start.
-# So if Code-Server is already running: docker restart Code-Server after this script runs.
+#   max_user_watches    — SHARED budget across ALL users and containers on the system.
+#                         Each watched file or directory costs one watch. Default 8192 —
+#                         VSCode alone needs 50K–200K for large workspaces. Combined
+#                         usage of Sonarr, Radarr, Lidarr, Emby, Nextcloud, Code-Server
+#                         easily exceeds 512K on a busy server.
 #
-# ── CONSUMERS ON THIS STACK ───────────────────────────────────────────────────────────────────
-#   Emby           — watches all media library paths (1 watch per folder)
-#   Sonarr         — watches TV_Shows folder tree
-#   Radarr         — watches Movies folder tree
-#   Lidarr         — watches Music folder tree
-#   Nextcloud      — watches data directory for changes
-#   Code-Server    — watches entire workspace (can be 50K-200K with node_modules)
-#   AdGuard Home   — watches config directory
-#   + all other containers using inotify internally
+#   max_queued_events   — max events buffered before the kernel drops them. Low value =
+#                         events silently lost during high-activity bursts. Default 16384.
 #
-# ── SAFEGUARDS ────────────────────────────────────────────────────────────────────────────────
-#   acquire_lock     — prevents duplicate runs at array start
-#   Root check       — sysctl writes require root
-#   validate_unraid  — notify validated before use
-#   Silent on success — runs every boot, no noise when already correct
-#   Only warns on changes or failures
+# Why 1M Watches
+#   Raising max_user_watches to 1048576 (1M) gives sufficient headroom for all
+#   containers combined — safe on 128GB RAM (~128MB kernel use for the pool).
 #
-# ── CONFIGURATION (master.conf) ───────────────────────────────────────────────────────────────
-#   INOTIFY_MAX_INSTANCES     — default 1024
-#   INOTIFY_MAX_WATCHES       — default 1048576 (1M)
-#   INOTIFY_MAX_QUEUED_EVENTS — default 32768
+# Idempotent Per-Setting
+#   Each sysctl value is read before writing. Only changed if different from target —
+#   no-op on boots where limits are already correct.
+#
+# ==============================================================================================
+# OPERATIONAL SAFEGUARDS
+# ==============================================================================================
+#
+# Root Required
+#   sysctl writes require root.
+#
+# Single Instance Lock
+#   acquire_lock prevents duplicate runs at array start.
+#
+# Silent on Success
+#   Runs every boot — no noise when already correct.
+#
+# ==============================================================================================
+# CONFIGURATION
+# ==============================================================================================
+#
+# master.conf
+#
+#   INOTIFY_MAX_INSTANCES
+#       Max inotify fd objects per user. (default: 1024)
+#
+#   INOTIFY_MAX_WATCHES
+#       Max watched files/dirs shared across all users and containers. (default: 1048576)
+#
+#   INOTIFY_MAX_QUEUED_EVENTS
+#       Max events buffered before kernel drops them. (default: 32768)
+#
+# ==============================================================================================
+# RUNTIME MODES
+# ==============================================================================================
+#
+# inotify_tuning.sh
+#     Apply inotify limits. No-op per setting if already at target.
+#
+# inotify_tuning.sh --dry-run
+#     Show current vs target for each limit. No sysctl writes.
+#
+# inotify_tuning.sh --status
+#     Show current vs target, active instance count, and top consumers by PID.
+#
+# inotify_tuning.sh --log
+#     Verbose output — show each sysctl check and result.
 #
-# ── USAGE ─────────────────────────────────────────────────────────────────────────────────────
-#   inotify_tuning.sh              — normal run (apply settings)
-#   inotify_tuning.sh --dry-run    — show what would change
-#   inotify_tuning.sh --status     — show current vs target values and top consumers
-#   inotify_tuning.sh --log        — verbose output
 # ==============================================================================================
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"