feat(infra): add TagMapper with address mapping, value parsing, and quality mapping

infra/lmxfakeproxy/TagMapper.cs

@@ -0,0 +1,43 @@
+using LmxFakeProxy.Grpc;
+
+namespace LmxFakeProxy;
+
+public class TagMapper
+{
+    private readonly string _prefix;
+
+    public TagMapper(string prefix)
+    {
+        _prefix = prefix;
+    }
+
+    public string ToOpcNodeId(string lmxTag) => $"{_prefix}{lmxTag}";
+
+    public static object ParseWriteValue(string value)
+    {
+        if (double.TryParse(value, System.Globalization.NumberStyles.Float,
+            System.Globalization.CultureInfo.InvariantCulture, out var d))
+            return d;
+        if (bool.TryParse(value, out var b))
+            return b;
+        return value;
+    }
+
+    public static string MapQuality(uint statusCode)
+    {
+        if (statusCode == 0) return "Good";
+        if ((statusCode & 0x80000000) != 0) return "Bad";
+        return "Uncertain";
+    }
+
+    public static VtqMessage ToVtqMessage(string tag, object? value, DateTime timestampUtc, uint statusCode)
+    {
+        return new VtqMessage
+        {
+            Tag = tag,
+            Value = value?.ToString() ?? string.Empty,
+            TimestampUtcTicks = timestampUtc.Ticks,
+            Quality = MapQuality(statusCode)
+        };
+    }
+}