Document the Galaxy runtime status feature across the architecture guides so operators and future maintainers can find probe machinery, config fields, dashboard panel, and HealthCheck Rule 2e without having to dig through runtimestatus.md or service_info.md

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/Configuration.md

@@ -74,6 +74,8 @@ Controls the MXAccess runtime connection used for live tag reads and writes. Def
 | `AutoReconnect` | `bool` | `true` | Automatically re-establish dropped MXAccess sessions |
 | `ProbeTag` | `string?` | `null` | Optional tag used to verify the runtime returns fresh data |
 | `ProbeStaleThresholdSeconds` | `int` | `60` | Seconds a probe value may remain unchanged before the connection is considered stale |
+| `RuntimeStatusProbesEnabled` | `bool` | `true` | Advises `<Host>.ScanState` on every deployed `$WinPlatform` and `$AppEngine` to track per-host runtime state. Drives the Galaxy Runtime dashboard panel, HealthCheck Rule 2e, and the Read-path short-circuit that invalidates OPC UA variable quality when a host is Stopped. Set `false` to return to legacy behavior where host state is invisible and the bridge serves whatever quality MxAccess reports for individual tags. See [MXAccess Bridge](MxAccessBridge.md#per-host-runtime-status-probes-hostscanstate) |
+| `RuntimeStatusUnknownTimeoutSeconds` | `int` | `15` | Maximum seconds to wait for the initial probe callback before marking a host as Stopped. Only applies to the Unknown → Stopped transition; Running hosts never time out because `ScanState` is delivered on-change only. A value below 5s triggers a validator warning |
 
 ### GalaxyRepository
 
@@ -255,6 +257,7 @@ Three boolean properties act as feature flags that control optional subsystems:
 - `Historian.ServerName` (or `Historian.ServerNames`) must not be empty when `Historian.Enabled = true`
 - `Historian.FailureCooldownSeconds` must be zero or positive
 - `Historian.ServerName` is set alongside a non-empty `Historian.ServerNames` emits a warning (single ServerName is ignored)
+- `MxAccess.RuntimeStatusUnknownTimeoutSeconds` below 5s emits a warning (below the reasonable floor for MxAccess initial-resolution latency)
 - `OpcUa.ApplicationUri` must be set when `Redundancy.Enabled = true`
 - `Redundancy.ServiceLevelBase` must be between 1 and 255
 - `Redundancy.ServerUris` should contain at least 2 entries when enabled
@@ -305,7 +308,9 @@ Integration tests use this constructor to inject substitute implementations of `
     "MonitorIntervalSeconds": 5,
     "AutoReconnect": true,
     "ProbeTag": null,
-    "ProbeStaleThresholdSeconds": 60
+    "ProbeStaleThresholdSeconds": 60,
+    "RuntimeStatusProbesEnabled": true,
+    "RuntimeStatusUnknownTimeoutSeconds": 15
   },
   "GalaxyRepository": {
     "ConnectionString": "Server=localhost;Database=ZB;Integrated Security=true;",