fix(adminui): Monaco text syncs on demand, diagnostics are sequenced, Problems list (D1)

R04:P1 - the editor no longer ships its full text JS->.NET on every keystroke. It reports
at blur, and ScriptEdit / the VirtualTag modal read the authoritative value with
MonacoEditor.GetValueAsync at Save (validation runs after the pull). The Blazor hub's
MaximumReceiveMessageSize is raised from 32 KB to 1 MB. The JS refuses a value that
would not fit instead of sending an oversize frame, and Save surfaces that refusal
rather than persisting stale source.

R04:P9 - diagnostics carry a generation counter and an AbortController. Every edit aborts
the in-flight request, and only the response for the current text is applied.

R04:S2 - the always-empty inlay-hints provider, endpoint, service method and contracts
are removed.

R04:S3 - MarkersChanged is typed (DiagnosticMarker) and feeds a new ScriptProblemsList.
Clicking a problem calls RevealLineAsync. Markers cross to .NET only when a list
subscribes.

Refs #745

Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT

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

@@ -1,5 +1,6 @@
 @namespace ZB.MOM.WW.OtOpcUa.AdminUI.Components.Shared
 @using Microsoft.Extensions.Logging
+@using ZB.MOM.WW.OtOpcUa.AdminUI.ScriptAnalysis
 @implements IAsyncDisposable
 @inject IJSRuntime JS
 @inject Microsoft.Extensions.Logging.ILogger<MonacoEditor> Logger
@@ -22,7 +23,13 @@
      style="height: @Height; border: 1px solid var(--bs-border-color); border-radius: 0.25rem; overflow: hidden;"></div>
 
 @code {
+    /// <summary>
+    /// The editor text. Two-way bound, but the editor reports edits back only when it loses focus — never per
+    /// keystroke (each report is one circuit message carrying the whole script). A page that persists the text
+    /// must read the authoritative current value with <see cref="GetValueAsync"/> at save time.
+    /// </summary>
     [Parameter] public string Value { get; set; } = "";
+    /// <summary>Raised with the editor text when the editor loses focus after an edit (and from <see cref="GetValueAsync"/>).</summary>
     [Parameter] public EventCallback<string> ValueChanged { get; set; }
     [Parameter] public string Language { get; set; } = "csharp";
     [Parameter] public string Height { get; set; } = "320px";
@@ -37,11 +44,11 @@
     [Parameter] public string? EquipmentId { get; set; }
 
     /// <summary>
-    /// Fires whenever Monaco's marker set updates (after the 500 ms diagnostic
-    /// debounce). The marker DTO is not modelled yet — typed as object[] until a
-    /// later task wires the Roslyn-backed diagnostics.
+    /// Fires whenever Monaco's diagnostic marker set updates (after the 500 ms debounce, and only for the response
+    /// to the CURRENT text — superseded responses are dropped in the JS). Feeds <c>ScriptProblemsList</c>; the
+    /// markers are sent from JS only when this callback has a subscriber.
     /// </summary>
-    [Parameter] public EventCallback<object[]> MarkersChanged { get; set; }
+    [Parameter] public EventCallback<IReadOnlyList<DiagnosticMarker>> MarkersChanged { get; set; }
 
     private ElementReference _hostRef;
     private DotNetObjectReference<MonacoEditor>? _dotNetRef;
@@ -69,7 +76,9 @@
                         value = Value ?? "",
                         language = Language,
                         readOnly = ReadOnly,
-                        equipmentId = EquipmentId
+                        equipmentId = EquipmentId,
+                        maxSyncBytes = ScriptEditorLimits.MaxEditorSyncBytes,
+                        reportMarkers = MarkersChanged.HasDelegate
                     },
                     _dotNetRef);
                 _initialized = true;
@@ -126,9 +135,47 @@
         return ValueChanged.InvokeAsync(_lastSentValue);
     }
 
+    /// <summary>
+    /// Reads the editor's current text on demand (call it at Save), raises <see cref="ValueChanged"/> when it
+    /// differs from the last value reported, and returns it. Before the editor is live (prerender, failed init)
+    /// the bound <see cref="Value"/> is authoritative and is returned as-is.
+    /// </summary>
+    /// <returns>The current text, or an error (e.g. the script is too large to send) — never a stale value.</returns>
+    public async Task<EditorReadResult> GetValueAsync()
+    {
+        if (!_initialized) return new EditorReadResult(Value ?? "", null);
+        string? current;
+        try
+        {
+            current = await JS.InvokeAsync<string?>("MonacoBlazor.getValue", _id);
+        }
+        catch (JSDisconnectedException)
+        {
+            return new EditorReadResult(null, "The connection to the editor was lost; reload the page and try again.");
+        }
+        catch (JSException ex)
+        {
+            Logger.LogWarning(ex, "Monaco editor {EditorId}: failed to read the editor text.", _id);
+            // JSException.Message carries the JS stack after the first line; the author needs only the reason.
+            return new EditorReadResult(null, ex.Message.Split('\n', 2)[0].Trim());
+        }
+        if (current is null) return new EditorReadResult(Value ?? "", null);   // editor already disposed
+        await OnValueChanged(current);
+        return new EditorReadResult(current, null);
+    }
+
+    /// <summary>The outcome of <see cref="GetValueAsync"/>: the text, or why it could not be read.</summary>
+    /// <param name="Value">The editor text; null when <paramref name="Error"/> is set.</param>
+    /// <param name="Error">Why the text could not be read; null on success.</param>
+    public sealed record EditorReadResult(string? Value, string? Error)
+    {
+        /// <summary>True when <see cref="Value"/> holds the editor text.</summary>
+        public bool Ok => Error is null;
+    }
+
     [JSInvokable]
-    public Task OnMarkersChanged(object[] markers) =>
-        MarkersChanged.InvokeAsync(markers ?? Array.Empty<object>());
+    public Task OnMarkersChanged(DiagnosticMarker[]? markers) =>
+        MarkersChanged.InvokeAsync(markers ?? Array.Empty<DiagnosticMarker>());
 
     /// <summary>Programmatic scroll-to-line (called by the problems panel).</summary>
     public async Task RevealLineAsync(int line, int column = 1)