Phase 3 PR 36 — AVEVA prerequisites test-support library. New tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport multi-targeted class library (net10.0 + net48 so both the modern and the MXAccess-COM x86 test projects can consume it) that probes every piece of the AVEVA System Platform + OtOpcUa stack a live-Galaxy test depends on and returns a structured PrerequisiteReport. Closes the gap where live-smoke tests silently returned 'unreachable' without telling operators which specific piece failed.

AvevaPrerequisites.CheckAllAsync walks eight probe categories producing PrerequisiteCheck rows each with Name (e.g. 'service:aaBootstrap', 'sql:ZB', 'com:LMXProxy', 'registry:ArchestrA.Framework'), Category (AvevaCoreService / AvevaSoftService / AvevaInstall / MxAccessCom / GalaxyRepository / AvevaHistorian / OtOpcUaService / Environment), Status (Pass / Warn / Fail / Skip), and operator-facing Detail message. Report aggregates them: IsLivetestReady (no Fails anywhere) and IsAvevaSideReady (AVEVA-side categories pass, our v2 services can be absent while still considering the environment AVEVA-ready) so different test tiers can use the right threshold.
Individual probes: ServiceProbe.Check queries the Windows Service Control Manager via System.ServiceProcess.ServiceController — treats DemandStart+Stopped as Warn (NmxSvc is DemandStart by design; master pulls it up) but AutoStart+Stopped as Fail; not-installed is Fail for hard-required services, Warn for soft ones; non-Windows hosts get Skip; transitional states like StartPending get Warn with a 'try again' hint. RegistryProbe reads HKLM\SOFTWARE\WOW6432Node\ArchestrA\{Framework,Framework\Platform,MSIInstall} — Framework key presence + populated InstallPath/RootPath values mean System Platform installed; PfeConfigOptions in the Platform subkey (format 'PlatformId=N,EngineId=N,...') indicates a Platform has been deployed from the IDE (PlatformId=0 means never deployed — MXAccess will connect but every subscription will be Bad quality); RebootRequired='True' under MSIInstall surfaces as a loud warn since post-patch behavior is undefined. MxAccessComProbe resolves the LMXProxy.LMXProxyServer ProgID → CLSID → HKLM\SOFTWARE\Classes\WOW6432Node\CLSID\{guid}\InprocServer32, verifying the registered file exists on disk (catches the orphan-registry case where a previous uninstall left the ProgID registered but the DLL is gone — distinguishes it from the 'totally not installed' case by message); also emits a Warn when the test process is 64-bit (MXAccess COM activation fails with REGDB_E_CLASSNOTREG 0x80040154 regardless of registration, so seeing this warning tells operators why the activation would fail even on a fully-installed machine). SqlProbe tests Galaxy Repository via Microsoft.Data.SqlClient using the Windows-auth localhost connection string the repo code defaults to — distinguishes 'SQL Server unreachable' (connection fails) from 'ZB database does not exist' (SELECT DB_ID('ZB') returns null) because they have different remediation paths (sc.exe start MSSQLSERVER vs. restore from .cab backup); a secondary CheckDeployedObjectCountAsync query on 'gobject WHERE deployed_version > 0' warns when the count is zero because discovery smoke tests will return empty hierarchies. NamedPipeProbe opens a 2s NamedPipeClientStream against OtOpcUaGalaxyHost's pipe ('OtOpcUaGalaxy' per the installer default) — pipe accepting a connection proves the Host service is listening; disconnects immediately so we don't consume a session slot.
Service lists kept as internal static data so tests can inspect + override: CoreServices (aaBootstrap + aaGR + NmxSvc + MSSQLSERVER — hard fail if missing), SoftServices (aaLogger + aaUserValidator + aaGlobalDataCacheMonitorSvr — warn only; stack runs without them but diagnostics/auth are degraded), HistorianServices (aahClientAccessPoint + aahGateway — opt-in via Options.CheckHistorian, only matters for HistoryRead IPC paths), OtOpcUaServices (our OtOpcUaGalaxyHost hard-required for end-to-end live tests + OtOpcUa warn + GLAuth warn). Narrower entry points CheckRepositoryOnlyAsync and CheckGalaxyHostPipeOnlyAsync for tests that only care about specific subsystems — avoid paying the full probe cost on every GalaxyRepositoryLiveSmokeTests fact.
Multi-targeting mechanics: System.ServiceProcess.ServiceController + Microsoft.Win32.Registry are NuGet packages on net10 but in-box BCL references on net48; csproj conditions Package vs Reference by TargetFramework. Microsoft.Data.SqlClient v6 supports both frameworks so single PackageReference. Net48Polyfills.cs provides IsExternalInit shim (records/init-only setters) and SupportedOSPlatformAttribute stub so the same Probe sources compile on both frameworks without per-callsite preprocessor guards — lets Roslyn's platform-compatibility analyzer stay useful on net10 without breaking net48 builds.
Existing GalaxyRepositoryLiveSmokeTests updated to delegate its skip decision to AvevaPrerequisites.CheckRepositoryOnlyAsync (legacy ZbReachableAsync kept as a compatibility adapter so the in-test 'if (!await ZbReachableAsync()) return;' pattern keeps working while the surrounding fixtures gradually migrate to Assert.Skip-with-reason). Slnx file registers the new project.
Tests — AvevaPrerequisitesLiveTests (8 new Integration cases, Category=LiveGalaxy): the helper correctly reports Framework install (registry pass), aaBootstrap Running (service pass), aaGR Running (service pass), MxAccess COM registered (com pass), ZB database reachable (sql pass), deployed-object count > 0 (warn-upgraded-to-pass because this box has 49 objects deployed), the AVEVA side is ready even when our own services (OtOpcUaGalaxyHost) aren't installed yet (IsAvevaSideReady=true), and the helper emits rows for OtOpcUaGalaxyHost + OtOpcUa + GLAuth even when not installed (regression guard — nobody can accidentally ship a check that omits our own services). Full Galaxy.Host.Tests Category=LiveGalaxy suite: 13 pass (5 prior smoke + 8 new prerequisites). Full solution build clean, 0 errors.
What's NOT in this PR: end-to-end Galaxy stack smoke (Proxy → Host pipe → MXAccess → real Galaxy tag). That's the next PR — this one is the gate the end-to-end smoke will call first to produce actionable skip messages instead of silent returns.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/Probes/MxAccessComProbe.cs

@@ -0,0 +1,102 @@
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.Probes;
+
+/// <summary>
+///     Confirms MXAccess COM server registration by resolving the
+///     <c>LMXProxy.LMXProxyServer</c> ProgID to its CLSID, then checking that the CLSID's
+///     32-bit <c>InprocServer32</c> entry points at a file that exists on disk.
+/// </summary>
+/// <remarks>
+///     A common failure mode on partial installs: ProgID is registered but the CLSID
+///     InprocServer32 DLL is missing (previous install uninstalled but registry orphan remains).
+///     This probe surfaces that case with an actionable message instead of the
+///     <c>0x80040154 REGDB_E_CLASSNOTREG</c> you'd see from a late COM activation failure.
+/// </remarks>
+public static class MxAccessComProbe
+{
+    public const string ProgId = "LMXProxy.LMXProxyServer";
+    public const string VersionedProgId = "LMXProxy.LMXProxyServer.1";
+
+    public static PrerequisiteCheck Check()
+    {
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                PrerequisiteStatus.Skip, "COM registration probes only run on Windows.");
+        }
+        return CheckWindows();
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static PrerequisiteCheck CheckWindows()
+    {
+        try
+        {
+            var (clsid, dll) = RegistryProbe.ResolveProgIdToInproc(ProgId);
+            if (clsid is null)
+            {
+                return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                    PrerequisiteStatus.Fail,
+                    $"ProgID {ProgId} not registered — MXAccess COM server isn't installed. " +
+                    $"Install System Platform's MXAccess component and re-run.");
+            }
+
+            if (string.IsNullOrWhiteSpace(dll))
+            {
+                return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                    PrerequisiteStatus.Fail,
+                    $"ProgID {ProgId} → CLSID {clsid} but InprocServer32 is empty. " +
+                    $"Registry is orphaned; re-register with: regsvr32 /s LmxProxy.dll (from an elevated cmd in the Framework bin dir).");
+            }
+
+            // Resolve the recorded path — sometimes registered as a bare filename that the COM
+            // runtime resolves via the current process's DLL-search path. Accept either an
+            // absolute path that exists, or a bare filename whose resolution we can't verify
+            // without loading it (treat as Pass-with-note).
+            if (Path.IsPathRooted(dll))
+            {
+                if (!File.Exists(dll))
+                {
+                    return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                        PrerequisiteStatus.Fail,
+                        $"ProgID {ProgId} → CLSID {clsid} → InprocServer32 {dll}, but the file is missing. " +
+                        $"Re-install the Framework or restore from backup.");
+                }
+                return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                    PrerequisiteStatus.Pass,
+                    $"ProgID {ProgId} → {dll} (file exists).");
+            }
+
+            return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                PrerequisiteStatus.Pass,
+                $"ProgID {ProgId} → {dll} (bare filename — relies on PATH resolution at COM activation time).");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                PrerequisiteStatus.Warn,
+                $"Probe failed: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+
+    /// <summary>
+    ///     Warn when running as a 64-bit process — MXAccess COM activation will fail with
+    ///     <c>0x80040154</c> regardless of registration state. The production drivers run net48
+    ///     x86; xunit hosts run 64-bit by default so this often surfaces first.
+    /// </summary>
+    public static PrerequisiteCheck CheckProcessBitness()
+    {
+        if (Environment.Is64BitProcess)
+        {
+            return new PrerequisiteCheck("env:ProcessBitness", PrerequisiteCategory.Environment,
+                PrerequisiteStatus.Warn,
+                "Test host is 64-bit. Direct MXAccess COM activation would fail with REGDB_E_CLASSNOTREG (0x80040154); " +
+                "the production driver workaround is to run Galaxy.Host as a 32-bit process. Tests that only " +
+                "talk to the Host service over the named pipe aren't affected.");
+        }
+        return new PrerequisiteCheck("env:ProcessBitness", PrerequisiteCategory.Environment,
+            PrerequisiteStatus.Pass, "Test host is 32-bit.");
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/Probes/NamedPipeProbe.cs

@@ -0,0 +1,59 @@
+using System.IO.Pipes;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.Probes;
+
+/// <summary>
+///     Verifies the <c>OtOpcUaGalaxyHost</c> named-pipe endpoint is accepting connections —
+///     the handshake the Proxy performs at boot. A clean pipe connect without sending any
+///     framed message proves the Host service is listening; we disconnect immediately so we
+///     don't consume a session slot.
+/// </summary>
+/// <remarks>
+///     Default pipe name matches the installer script's <c>OTOPCUA_GALAXY_PIPE</c> default.
+///     Override when the Host service was installed with a non-default name (custom deployments).
+/// </remarks>
+public static class NamedPipeProbe
+{
+    public const string DefaultGalaxyHostPipeName = "OtOpcUaGalaxy";
+
+    public static async Task<PrerequisiteCheck> CheckGalaxyHostPipeAsync(
+        string? pipeName = null, CancellationToken ct = default)
+    {
+        pipeName ??= DefaultGalaxyHostPipeName;
+        try
+        {
+            using var client = new NamedPipeClientStream(
+                serverName: ".",
+                pipeName: pipeName,
+                direction: PipeDirection.InOut,
+                options: PipeOptions.Asynchronous);
+            using var cts = CancellationTokenSource.CreateLinkedTokenSource(ct);
+            cts.CancelAfter(TimeSpan.FromSeconds(2));
+            await client.ConnectAsync(cts.Token);
+
+            return new PrerequisiteCheck("pipe:OtOpcUaGalaxyHost", PrerequisiteCategory.OtOpcUaService,
+                PrerequisiteStatus.Pass,
+                $@"Pipe \\.\pipe\{pipeName} accepted a connection — OtOpcUaGalaxyHost is listening.");
+        }
+        catch (OperationCanceledException)
+        {
+            return new PrerequisiteCheck("pipe:OtOpcUaGalaxyHost", PrerequisiteCategory.OtOpcUaService,
+                PrerequisiteStatus.Fail,
+                $@"Pipe \\.\pipe\{pipeName} not connectable within 2s — OtOpcUaGalaxyHost service isn't running. " +
+                "Start with: sc.exe start OtOpcUaGalaxyHost");
+        }
+        catch (TimeoutException)
+        {
+            return new PrerequisiteCheck("pipe:OtOpcUaGalaxyHost", PrerequisiteCategory.OtOpcUaService,
+                PrerequisiteStatus.Fail,
+                $@"Pipe \\.\pipe\{pipeName} connect timed out — service may be starting or stuck. " +
+                "Check: sc.exe query OtOpcUaGalaxyHost");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("pipe:OtOpcUaGalaxyHost", PrerequisiteCategory.OtOpcUaService,
+                PrerequisiteStatus.Fail,
+                $@"Pipe \\.\pipe\{pipeName} connect failed: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/Probes/RegistryProbe.cs

@@ -0,0 +1,162 @@
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using Microsoft.Win32;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.Probes;
+
+/// <summary>
+///     Reads HKLM registry keys to confirm ArchestrA Framework / System Platform install
+///     markers. Matches the registered paths documented in
+///     <c>docs/v2/implementation/</c> — System Platform is 32-bit so keys live under
+///     <c>HKLM\SOFTWARE\WOW6432Node\ArchestrA\...</c>.
+/// </summary>
+public static class RegistryProbe
+{
+    // Canonical install roots per the research on our dev box (System Platform 2020 R2).
+    public const string ArchestrARootKey = @"SOFTWARE\WOW6432Node\ArchestrA";
+    public const string FrameworkKey = @"SOFTWARE\WOW6432Node\ArchestrA\Framework";
+    public const string PlatformKey = @"SOFTWARE\WOW6432Node\ArchestrA\Framework\Platform";
+    public const string MsiInstallKey = @"SOFTWARE\WOW6432Node\ArchestrA\MSIInstall";
+
+    public static PrerequisiteCheck CheckFrameworkInstalled()
+    {
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.Framework", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Skip, "Registry probes only run on Windows.");
+        }
+        return FrameworkInstalledWindows();
+    }
+
+    public static PrerequisiteCheck CheckPlatformDeployed()
+    {
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.Platform", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Skip, "Registry probes only run on Windows.");
+        }
+        return PlatformDeployedWindows();
+    }
+
+    public static PrerequisiteCheck CheckRebootPending()
+    {
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.RebootPending", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Skip, "Registry probes only run on Windows.");
+        }
+        return RebootPendingWindows();
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static PrerequisiteCheck FrameworkInstalledWindows()
+    {
+        try
+        {
+            using var key = Registry.LocalMachine.OpenSubKey(FrameworkKey);
+            if (key is null)
+            {
+                return new PrerequisiteCheck("registry:ArchestrA.Framework", PrerequisiteCategory.AvevaInstall,
+                    PrerequisiteStatus.Fail,
+                    $"Missing {FrameworkKey} — ArchestrA Framework isn't installed. Install AVEVA System Platform from the setup media.");
+            }
+
+            var installPath = key.GetValue("InstallPath") as string;
+            var rootPath = key.GetValue("RootPath") as string;
+            if (string.IsNullOrWhiteSpace(installPath) || string.IsNullOrWhiteSpace(rootPath))
+            {
+                return new PrerequisiteCheck("registry:ArchestrA.Framework", PrerequisiteCategory.AvevaInstall,
+                    PrerequisiteStatus.Warn,
+                    $"Framework key exists but InstallPath/RootPath values missing — install may be incomplete.");
+            }
+
+            return new PrerequisiteCheck("registry:ArchestrA.Framework", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Pass,
+                $"Installed at {installPath} (RootPath {rootPath}).");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.Framework", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Warn,
+                $"Probe failed: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static PrerequisiteCheck PlatformDeployedWindows()
+    {
+        try
+        {
+            using var key = Registry.LocalMachine.OpenSubKey(PlatformKey);
+            var pfeConfig = key?.GetValue("PfeConfigOptions") as string;
+            if (string.IsNullOrWhiteSpace(pfeConfig))
+            {
+                return new PrerequisiteCheck("registry:ArchestrA.Platform.Deployed", PrerequisiteCategory.AvevaInstall,
+                    PrerequisiteStatus.Warn,
+                    $"No Platform object deployed locally (Platform\\PfeConfigOptions empty). MXAccess will connect but subscriptions will fail. Deploy a Platform from the IDE.");
+            }
+
+            // PfeConfigOptions format: "PlatformId=N,EngineId=N,EngineName=...,..."
+            // A non-deployed state leaves PlatformId=0 or the key empty.
+            if (pfeConfig.Contains("PlatformId=0,", StringComparison.OrdinalIgnoreCase))
+            {
+                return new PrerequisiteCheck("registry:ArchestrA.Platform.Deployed", PrerequisiteCategory.AvevaInstall,
+                    PrerequisiteStatus.Warn,
+                    $"Platform never deployed (PfeConfigOptions has PlatformId=0). Deploy a Platform from the IDE before running live tests.");
+            }
+
+            return new PrerequisiteCheck("registry:ArchestrA.Platform.Deployed", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Pass,
+                $"Platform deployed ({pfeConfig}).");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.Platform.Deployed", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Warn,
+                $"Probe failed: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static PrerequisiteCheck RebootPendingWindows()
+    {
+        try
+        {
+            using var key = Registry.LocalMachine.OpenSubKey(MsiInstallKey);
+            var rebootRequired = key?.GetValue("RebootRequired") as string;
+            if (string.Equals(rebootRequired, "True", StringComparison.OrdinalIgnoreCase))
+            {
+                return new PrerequisiteCheck("registry:ArchestrA.RebootPending", PrerequisiteCategory.AvevaInstall,
+                    PrerequisiteStatus.Warn,
+                    "An ArchestrA patch has been installed but the machine hasn't rebooted. Post-patch behavior is undefined until a reboot.");
+            }
+            return new PrerequisiteCheck("registry:ArchestrA.RebootPending", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Pass,
+                "No pending reboot flagged.");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.RebootPending", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Warn,
+                $"Probe failed: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+
+    /// <summary>
+    ///     Read the registered <see cref="ComProgIdCheck"/> CLSID for the given ProgID and
+    ///     resolve the 32-bit <c>InprocServer32</c> file path. Returns null when either is missing.
+    /// </summary>
+    [SupportedOSPlatform("windows")]
+    internal static (string? Clsid, string? InprocDllPath) ResolveProgIdToInproc(string progId)
+    {
+        using var progIdKey = Registry.ClassesRoot.OpenSubKey($@"{progId}\CLSID");
+        var clsid = progIdKey?.GetValue(null) as string;
+        if (string.IsNullOrWhiteSpace(clsid)) return (null, null);
+
+        // 32-bit COM server under Wow6432Node\CLSID\{guid}\InprocServer32 default value.
+        using var inproc = Registry.LocalMachine.OpenSubKey(
+            $@"SOFTWARE\Classes\WOW6432Node\CLSID\{clsid}\InprocServer32");
+        var dll = inproc?.GetValue(null) as string;
+        return (clsid, dll);
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/Probes/ServiceProbe.cs

@@ -0,0 +1,85 @@
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using System.ServiceProcess;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.Probes;
+
+/// <summary>
+///     Queries the Windows Service Control Manager to report whether a named service is
+///     installed, its current state, and its start type. Non-Windows hosts return Skip.
+/// </summary>
+public static class ServiceProbe
+{
+    public static PrerequisiteCheck Check(
+        string serviceName,
+        PrerequisiteCategory category,
+        bool hardRequired,
+        string whatItDoes)
+    {
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            return new PrerequisiteCheck(
+                Name: $"service:{serviceName}",
+                Category: category,
+                Status: PrerequisiteStatus.Skip,
+                Detail: "Service probes only run on Windows.");
+        }
+
+        return CheckWindows(serviceName, category, hardRequired, whatItDoes);
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static PrerequisiteCheck CheckWindows(
+        string serviceName, PrerequisiteCategory category, bool hardRequired, string whatItDoes)
+    {
+        try
+        {
+            using var sc = new ServiceController(serviceName);
+            // Touch the Status to force the SCM lookup; if the service doesn't exist, this throws
+            // InvalidOperationException with message "Service ... was not found on computer.".
+            var status = sc.Status;
+            var startType = sc.StartType;
+
+            return status switch
+            {
+                ServiceControllerStatus.Running => new PrerequisiteCheck(
+                    $"service:{serviceName}", category, PrerequisiteStatus.Pass,
+                    $"Running ({whatItDoes})"),
+
+                // DemandStart services (like NmxSvc) that are Stopped are not necessarily a
+                // failure — the master service (aaBootstrap) brings them up on demand. Treat
+                // Stopped+Demand as Warn so operators know the situation but tests still proceed.
+                ServiceControllerStatus.Stopped when startType == ServiceStartMode.Manual =>
+                    new PrerequisiteCheck(
+                        $"service:{serviceName}", category, PrerequisiteStatus.Warn,
+                        $"Installed but Stopped (start type Manual — {whatItDoes}). " +
+                        "Will be pulled up on demand by the master service; fine for tests."),
+
+                ServiceControllerStatus.Stopped => Fail(
+                    $"Installed but Stopped. Start with: sc.exe start {serviceName}  ({whatItDoes})"),
+
+                _ => new PrerequisiteCheck(
+                    $"service:{serviceName}", category, PrerequisiteStatus.Warn,
+                    $"Transitional state {status} ({whatItDoes}) — try again in a few seconds."),
+            };
+
+            PrerequisiteCheck Fail(string detail) => new(
+                $"service:{serviceName}", category,
+                hardRequired ? PrerequisiteStatus.Fail : PrerequisiteStatus.Warn,
+                detail);
+        }
+        catch (InvalidOperationException ex) when (ex.Message.Contains("was not found", StringComparison.OrdinalIgnoreCase))
+        {
+            return new PrerequisiteCheck(
+                $"service:{serviceName}", category,
+                hardRequired ? PrerequisiteStatus.Fail : PrerequisiteStatus.Warn,
+                $"Not installed ({whatItDoes}). Install the relevant System Platform component and retry.");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck(
+                $"service:{serviceName}", category, PrerequisiteStatus.Warn,
+                $"Probe failed ({ex.GetType().Name}: {ex.Message}) — treat as unknown.");
+        }
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/Probes/SqlProbe.cs

@@ -0,0 +1,88 @@
+using Microsoft.Data.SqlClient;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.Probes;
+
+/// <summary>
+///     Verifies the Galaxy Repository SQL side: SQL Server reachable, <c>ZB</c> database
+///     present, and at least one deployed object exists (so live tests have something to read).
+///     Reuses the Windows-auth connection string the repo code defaults to.
+/// </summary>
+public static class SqlProbe
+{
+    public const string DefaultConnectionString =
+        "Server=localhost;Database=ZB;Integrated Security=True;TrustServerCertificate=True;Encrypt=False;Connect Timeout=3;";
+
+    public static async Task<PrerequisiteCheck> CheckZbDatabaseAsync(
+        string? connectionString = null, CancellationToken ct = default)
+    {
+        connectionString ??= DefaultConnectionString;
+        try
+        {
+            using var conn = new SqlConnection(connectionString);
+            await conn.OpenAsync(ct);
+
+            // DB_ID returns null when the database doesn't exist on the connected server — distinct
+            // failure mode from "server unreachable", deserves a distinct message.
+            using var cmd = conn.CreateCommand();
+            cmd.CommandText = "SELECT DB_ID('ZB')";
+            var dbIdObj = await cmd.ExecuteScalarAsync(ct);
+            if (dbIdObj is null || dbIdObj is DBNull)
+            {
+                return new PrerequisiteCheck("sql:ZB", PrerequisiteCategory.GalaxyRepository,
+                    PrerequisiteStatus.Fail,
+                    "SQL Server reachable but database ZB does not exist. " +
+                    "Create the Galaxy from the IDE or restore a .cab backup.");
+            }
+
+            return new PrerequisiteCheck("sql:ZB", PrerequisiteCategory.GalaxyRepository,
+                PrerequisiteStatus.Pass, "Connected; ZB database exists.");
+        }
+        catch (SqlException ex)
+        {
+            return new PrerequisiteCheck("sql:ZB", PrerequisiteCategory.GalaxyRepository,
+                PrerequisiteStatus.Fail,
+                $"SQL Server unreachable: {ex.Message}. Ensure MSSQLSERVER service is running (sc.exe start MSSQLSERVER) and TCP 1433 is open.");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("sql:ZB", PrerequisiteCategory.GalaxyRepository,
+                PrerequisiteStatus.Fail,
+                $"Unexpected probe error: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+
+    /// <summary>
+    ///     Returns the count of deployed Galaxy objects (<c>deployed_version &gt; 0</c>). Zero
+    ///     isn't a hard failure — lets someone boot a fresh Galaxy and still get meaningful
+    ///     test-suite output — but it IS a warning because any live-read smoke will have
+    ///     nothing to read.
+    /// </summary>
+    public static async Task<PrerequisiteCheck> CheckDeployedObjectCountAsync(
+        string? connectionString = null, CancellationToken ct = default)
+    {
+        connectionString ??= DefaultConnectionString;
+        try
+        {
+            using var conn = new SqlConnection(connectionString);
+            await conn.OpenAsync(ct);
+            using var cmd = conn.CreateCommand();
+            cmd.CommandText = "SELECT COUNT(*) FROM gobject WHERE deployed_version > 0";
+            var countObj = await cmd.ExecuteScalarAsync(ct);
+            var count = countObj is int i ? i : 0;
+
+            return count > 0
+                ? new PrerequisiteCheck("sql:ZB.deployedObjects", PrerequisiteCategory.GalaxyRepository,
+                    PrerequisiteStatus.Pass, $"{count} objects deployed — live reads have data to return.")
+                : new PrerequisiteCheck("sql:ZB.deployedObjects", PrerequisiteCategory.GalaxyRepository,
+                    PrerequisiteStatus.Warn,
+                    "ZB contains no deployed objects. Discovery smoke tests will return empty hierarchies; " +
+                    "deploy at least a Platform + AppEngine from the IDE to exercise the read path.");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("sql:ZB.deployedObjects", PrerequisiteCategory.GalaxyRepository,
+                PrerequisiteStatus.Warn,
+                $"Couldn't count deployed objects: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+}