feat: Enhance error logging for PDF preview failures and SQL timeouts

- Implemented a new method `ShapeTableNames` to gather entity and navigation table names, ensuring no blanks or duplicates are included.
- Updated `FdsMfrClient` to handle cases where schema queries return no tables, logging appropriate warnings and preventing misleading errors.
- Introduced `PdfPreviewAsync` in `IntranetController` to manage PDF preview rendering, capturing detailed logs for failures and notifying users with readable error messages.
- Added comprehensive unit tests for error logging and table name shaping to ensure robustness and correctness.
- Documented decision to persist user action failures to the `fds__admin_logdebug` table, enhancing support diagnostics.

Fuchs/code/FuchsIntranet.cs

@@ -229,13 +229,42 @@ public class FuchsUserIdentity
 public class FIS_SQLOptions : sqloptions
 {
     public FIS_SQLOptions(Dictionary<string, object>? context = null, ILogger? logger = null)
+        : this(context, logger, dbLog: (procedure, ex, data) => FuchsOcmsIntranet.Instance.debug_log(procedure, ex, data: data))
+    {
+    }
+
+    /// <summary>
+    /// Test seam: <paramref name="dbLog"/> receives what would otherwise go to
+    /// <see cref="Fuchs_intranet.debug_log"/> (code reference, exception, serialisable data).
+    /// </summary>
+    internal FIS_SQLOptions(Dictionary<string, object>? context, ILogger? logger,
+        Action<string, Exception?, object?> dbLog)
     {
         OnError = (procedure, ex, data) =>
         {
-            logger?.LogError(ex, "SQL error in {Procedure}: {Message} — context={@Context}",
-                procedure, ex.Message, context);
-            try { FuchsOcmsIntranet.Instance.debug_log($"SQL Error in {procedure}", ex, data: context); }
+            // OCORE hands the failing statement in `data` (new { sql = ... }); `context` is the
+            // caller's fn/id/code. Both are needed to attribute a timeout in the DB log — logging
+            // only the (usually null) context left every "SQL Error in getSQLDataSet" row without
+            // the SQL that timed out.
+            var logData = BuildLogData(context, data);
+            logger?.LogError(ex, "SQL error in {Procedure}: {Message} — sql={@Sql} context={@Context}",
+                procedure, ex.Message, data, context);
+            try { dbLog($"SQL Error in {procedure}", ex, logData); }
             catch { }
         };
     }
+
+    /// <summary>Merges the OCORE error payload (the SQL) with the caller context into one JSON-able object.</summary>
+    internal static Dictionary<string, object?> BuildLogData(IReadOnlyDictionary<string, object>? context, object? data)
+    {
+        var d = new Dictionary<string, object?>();
+        if (data != null)
+        {
+            // OCORE passes new { sql = "..." }; unwrap so the log column reads as the plain statement.
+            var sqlProp = data.GetType().GetProperty("sql");
+            d["sql"] = sqlProp?.GetValue(data) ?? data;
+        }
+        if (context is { Count: > 0 }) d["context"] = context;
+        return d;
+    }
 }