feat(monitoring): add automatic restart of unreachable customer containers

Some customers only regain access to their NetBird web UI after a manual
container restart, and until now that required someone to notice and do it
by hand. The scheduler now optionally probes each customer's actual
dashboard URL over HTTP(S) every poll interval (not just Docker container
state, since a container can be "running" while the web UI behind it still
doesn't respond) and restarts that customer's containers if it doesn't
answer, gated by a per-deployment cooldown to avoid restart loops on a
persistently broken customer.

New system setting "Automatic Restart of Unreachable Containers" (default
off) with a configurable cooldown. Every automatic restart is logged in the
affected customer's own log, same as a manual restart.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

app/models.py

@@ -96,6 +96,7 @@ class Deployment(Base):
     )
     deployed_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow)
     last_health_check: Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True)
+    last_auto_restart_at: Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True)
 
     __table_args__ = (
         CheckConstraint(
@@ -128,6 +129,9 @@ class Deployment(Base):
             "last_health_check": (
                 self.last_health_check.isoformat() if self.last_health_check else None
             ),
+            "last_auto_restart_at": (
+                self.last_auto_restart_at.isoformat() if self.last_auto_restart_at else None
+            ),
         }
 
 
@@ -212,6 +216,10 @@ class SystemConfig(Base):
     auto_update_apply_enabled: Mapped[bool] = mapped_column(Boolean, default=False)
     auto_update_last_run_at: Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True)
 
+    # Automatic restart of customer containers when found unreachable/not running
+    auto_restart_unreachable_enabled: Mapped[bool] = mapped_column(Boolean, default=False)
+    auto_restart_cooldown_minutes: Mapped[int] = mapped_column(Integer, default=30)
+
     # Master default for the NetBird *client* (peer) automatic-updates feature
     # (Settings > Clients > Automatic Updates inside each customer's own
     # NetBird dashboard) — pushed to customers via the NetBird Management API.
@@ -278,6 +286,8 @@ class SystemConfig(Base):
             "auto_update_last_run_at": (
                 self.auto_update_last_run_at.isoformat() if self.auto_update_last_run_at else None
             ),
+            "auto_restart_unreachable_enabled": bool(self.auto_restart_unreachable_enabled),
+            "auto_restart_cooldown_minutes": self.auto_restart_cooldown_minutes or 30,
             "netbird_client_auto_update_version": self.netbird_client_auto_update_version or "disabled",
             "netbird_client_auto_update_always": bool(self.netbird_client_auto_update_always),
             "created_at": self.created_at.isoformat() if self.created_at else None,