Docs: add network_watchdog to README-Watchdogs and Manual-Watchdogs

README-Watchdogs: tier diagram, folder relationship, script table,
  execution flow, state file table
Manual-Watchdogs: TOC entry, full System/network_watchdog.sh section
  (check sequence, config, usage, troubleshooting), config reference block

Watchdogs/README-Watchdogs.md

@@ -69,6 +69,7 @@ Container healing     docker_watchdog.sh     — memory, CPU, HTTP, required con
 System components     system_watchdog.sh     — thin orchestrator: storage + WebGUI health
   └─ System/          storage_watchdog.sh    — pool growth rate + runaway log detection
                       webgui_watchdog.sh     — WebGUI availability, nginx → php-fpm → emhttp
+                      network_watchdog.sh    — internet, DDNS sync, Tailscale, NPM proxy
 Last resort           stability_watchdog.sh  — reboot only when nothing else can recover
 ```
 
@@ -96,6 +97,7 @@ Orchestrators/
 Watchdogs/System/              ← called by system_watchdog.sh each cycle
   storage_watchdog.sh          pool growth rate + runaway log detection
   webgui_watchdog.sh           WebGUI availability — nginx → php-fpm → emhttp escalation
+  network_watchdog.sh          internet reachability, DDNS sync, Tailscale, NPM proxy
 
 Tools/
   watchdog_skip_list_manager.sh ◄────────────── docker_watchdog.sh writes skip list
@@ -121,6 +123,7 @@ Docker_Essentials/
 | `stability_watchdog.sh` | Last-resort server watchdog — reboots when healing has failed | `watchdog_orchestrator.sh` — 4th every minute |
 | `System/storage_watchdog.sh` | Pool growth rate + runaway log detection and remediation | `system_watchdog.sh` — every minute |
 | `System/webgui_watchdog.sh` | WebGUI availability — nginx → php-fpm → emhttp escalation | `system_watchdog.sh` — every minute |
+| `System/network_watchdog.sh` | Internet reachability, DDNS sync, Tailscale, NPM proxy | `system_watchdog.sh` — every minute |
 
 > `watchdog_orchestrator.sh` is in `Orchestrators/`. `watchdog_skip_list_manager.sh`
 > is in `Tools/`. Neither is a watchdog — they sit at the edges of this system.
@@ -170,6 +173,12 @@ Every minute — watchdog_orchestrator.sh fires:
     │       still down    → emhttp restart → wait → recheck
     │       all three failed → critical notify, manual intervention needed
     │
+    │  └─ network_watchdog.sh
+    │       internet check → fail = alert + skip remaining (prevents false positives)
+    │       DDNS: public IP vs dig @1.1.1.1 → mismatch = restart Cloudflare DDNS container
+    │       Tailscale: status Running → pass; not running = notify (no auto-restart)
+    │       NPM proxy: curl external URL → 2-strike system → restart NginxProxyManager
+    │
   Step 4 — stability_watchdog.sh
        checks the server itself — RAM, CPU temp, rootfs, FDs, kernel, daemon
        Tier 1 CRITICAL  → immediate reboot (no strikes)
@@ -189,3 +198,4 @@ Every minute — watchdog_orchestrator.sh fires:
 | `SYS_WATCHDOG_FAILED_FILE` | `docker_watchdog.sh` | `watchdog_skip_list_manager.sh` | Container skip list |
 | `STORAGE_WATCHDOG_STATE_FILE` | `System/storage_watchdog.sh` | itself | Growth + log strike counts |
 | `WATCHDOG_APPDATA_GROWTH_FILE` | `System/storage_watchdog.sh` | itself | Per-container size baseline for growth rate |
+| `NETWORK_WATCHDOG_NPM_STATE_FILE` | `System/network_watchdog.sh` | itself | NPM proxy strike count |