feat(mtconnect): warn at Test Connect and deploy when SampleCount >= the Agent bufferSize (#825)

Parse the /probe Header bufferSize; MTConnectDriverProbe reads sampleCount
(default 1000) and answers Ok with a WARNING message (amber chip in the
Test Connect button); InitializeAsync logs the same Warning and exposes
agentBufferSize on the diagnostics bag. Live-checked against the shared
cppagent fixture (bufferSize 16384).

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Drivers/DriverTestConnectButton.razor

@@ -12,7 +12,16 @@
 
     @if (_result is not null)
     {
-        @if (_result.Ok)
+        @if (_result.Ok && WarningOf(_result.Message) is { } warning)
+        {
+            @* Reachable but misconfigured (e.g. MTConnect SampleCount >= the Agent's bufferSize, #825): a probe
+               that answers Ok with a "WARNING:" message is shown amber with the warning, never a plain green OK. *@
+            <span class="chip chip-warn" title="@warning">
+                OK with warning &middot; @_result.LatencyMs?.ToString("F0") ms
+            </span>
+            <div class="small text-warning mt-1">@warning</div>
+        }
+        else if (_result.Ok)
         {
             <span class="chip chip-ok" title="@($"Probe succeeded in {_result.LatencyMs:F0} ms")">
                 OK &middot; @_result.LatencyMs?.ToString("F0") ms
@@ -28,6 +37,16 @@
 </div>
 
 @code {
+    /// <summary>The marker a probe puts in an <c>Ok</c> message to flag a warning (see <c>MTConnectDriverProbe</c>).</summary>
+    internal const string WarningMarker = "WARNING:";
+
+    /// <summary>The warning text after <see cref="WarningMarker"/>, or null when the message carries none.</summary>
+    internal static string? WarningOf(string? message)
+    {
+        var at = message?.IndexOf(WarningMarker, StringComparison.Ordinal) ?? -1;
+        return at < 0 ? null : message![(at + WarningMarker.Length)..].Trim();
+    }
+
     /// <summary>Driver type key — must match an installed <c>IDriverProbe.DriverType</c>.</summary>
     [Parameter, EditorRequired] public string DriverType { get; set; } = "";