Add Debug page and fix BLE communication issues

Major changes:
- Added Debug tab with real-time message logging and hex viewer
- Implemented timed data logging ($UMTDL command) per API v1.3
- Fixed BLE message parsing to handle notifications without line endings
- Added Schema 2 support (22-field timed logging packets)
- Updated Maglink BLE UUIDs (fff0/fff1/fff2)
- Added connection timeout (10s) to prevent hanging on unavailable devices
- Added connection status display and manual push-button logging trigger
- Improved retry logging with attempt numbers and delays
- Added console window allocation for Windows debug output
- Added BLE disconnect on app close

Bug fixes:
- Fixed device name filtering for Maglink (ML-* prefix)
- Fixed RtkGps enum reference in DeviceScanViewModel
- Fixed DebugMessage namespace (moved to Models)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

FieldLogger/Models/DebugMessage.cs

@@ -0,0 +1,24 @@
+namespace FieldLogger.Models;
+
+public class DebugMessage
+{
+    public DateTime Timestamp { get; set; }
+    public string Direction { get; set; } = "";
+    public string RawMessage { get; set; } = "";
+    public string Type { get; set; } = "";
+    public string? ParsedData { get; set; }
+    public string TypeColor { get; set; } = "Gray";
+    public bool HasParsedData => !string.IsNullOrEmpty(ParsedData);
+
+    public string HexBytes
+    {
+        get
+        {
+            if (string.IsNullOrEmpty(RawMessage))
+                return "[empty]";
+
+            var bytes = System.Text.Encoding.ASCII.GetBytes(RawMessage);
+            return BitConverter.ToString(bytes).Replace("-", " ");
+        }
+    }
+}

FieldLogger/Models/UmLogPacket.cs

@@ -10,12 +10,16 @@ public enum UmUtility { None = 0, Gas = 1, Power = 2, Communications = 3, Water
 
 public enum UmBatteryType { NotMeasured = 0, Alkaline = 1, AlkalineError = 2, Lithium = 3 }
 
+public enum UmLogType { PushButton = 0, TimeBased = 1 }
+
 /// <summary>
-/// A single push-button data-log packet from the UM locating receiver
-/// (PBDL schema 1, 21 comma-delimited fields).
+/// A single data-log packet from the UM locating receiver.
+/// Schema 1 (push-button): 21 fields
+/// Schema 2 (timed logging): 22 fields with LogType as first field
 /// </summary>
 public sealed class UmLogPacket
 {
+    public UmLogType? LogType { get; init; }      // Schema 2 only
     public UmMode Mode { get; init; }
     public int Frequency { get; init; }
     public UmFreqType FreqType { get; init; }
@@ -39,7 +43,8 @@ public sealed class UmLogPacket
     public bool MenuInUse { get; init; }
     public string RawText { get; init; } = "";
 
-    public const int FieldCount = 21;
+    public const int Schema1FieldCount = 21;
+    public const int Schema2FieldCount = 22;
 
     /// <summary>Depth converted to meters, when the raw string can be interpreted; otherwise null.</summary>
     public double? DepthMeters => TryParseDepthMeters(DepthRaw);
@@ -90,23 +95,45 @@ public sealed class UmLogPacket
     }
 
     /// <summary>
-    /// Parses a 21-field PBDL schema 1 packet. Returns null if the line does not look like a data packet.
+    /// Parses either Schema 1 (21 fields, push-button) or Schema 2 (22 fields, timed logging).
+    /// Returns null if the line does not look like a data packet.
     /// </summary>
     public static UmLogPacket? TryParse(string line)
     {
         var fields = line.Trim().Split(',');
-        if (fields.Length < FieldCount)
-            return null;
 
-        // First field must be a small integer (Mode 0-6) to qualify as a data packet.
-        if (!int.TryParse(fields[0], out var mode) || mode is < 0 or > 6)
-            return null;
+        // Try Schema 2 (22 fields with LogType)
+        if (fields.Length >= Schema2FieldCount)
+        {
+            if (int.TryParse(fields[0], out var logType) && logType is 0 or 1)
+            {
+                if (int.TryParse(fields[1], out var mode) && mode is >= 0 and <= 6)
+                {
+                    return ParseSchema2(fields, (UmLogType)logType, line);
+                }
+            }
+        }
 
+        // Try Schema 1 (21 fields without LogType)
+        if (fields.Length >= Schema1FieldCount)
+        {
+            if (int.TryParse(fields[0], out var mode) && mode is >= 0 and <= 6)
+            {
+                return ParseSchema1(fields, line);
+            }
+        }
+
+        return null;
+    }
+
+    private static UmLogPacket? ParseSchema1(string[] fields, string line)
+    {
         try
         {
             return new UmLogPacket
             {
-                Mode = (UmMode)mode,
+                LogType = null, // Schema 1 doesn't have LogType
+                Mode = (UmMode)ParseInt(fields[0]),
                 Frequency = ParseInt(fields[1]),
                 FreqType = (UmFreqType)ParseInt(fields[2]),
                 Signal = ParseInt(fields[3]),
@@ -136,6 +163,44 @@ public sealed class UmLogPacket
         }
     }
 
+    private static UmLogPacket? ParseSchema2(string[] fields, UmLogType logType, string line)
+    {
+        try
+        {
+            // Schema 2 has LogType at index 0, then same fields as Schema 1 shifted by 1
+            return new UmLogPacket
+            {
+                LogType = logType,
+                Mode = (UmMode)ParseInt(fields[1]),
+                Frequency = ParseInt(fields[2]),
+                FreqType = (UmFreqType)ParseInt(fields[3]),
+                Signal = ParseInt(fields[4]),
+                GainDb = ParseInt(fields[5]),
+                DepthRaw = fields[6].Trim(),
+                CurrentRaw = fields[7].Trim(),
+                CompassAngle = ParseInt(fields[8]),
+                GuidanceArrows = ParseInt(fields[9]),
+                LdPhase = ParseInt(fields[10]),
+                Clipping = ParseInt(fields[11]) != 0,
+                DepthCurrentSetting = ParseInt(fields[12]),
+                LrArrowStyle = ParseInt(fields[13]),
+                AudioVolume = ParseInt(fields[14]),
+                AudioModulation = ParseInt(fields[15]),
+                AudioSound = ParseInt(fields[16]),
+                BatteryVoltage = ParseDouble(fields[17]),
+                BatteryType = (UmBatteryType)ParseInt(fields[18]),
+                Backlight = ParseInt(fields[19]),
+                Utility = (UmUtility)ParseInt(fields[20]),
+                MenuInUse = ParseInt(fields[21]) != 0,
+                RawText = line.Trim(),
+            };
+        }
+        catch (FormatException)
+        {
+            return null;
+        }
+    }
+
     private static int ParseInt(string s) => int.Parse(s.Trim(), CultureInfo.InvariantCulture);
     private static double ParseDouble(string s) => double.Parse(s.Trim(), NumberStyles.Float, CultureInfo.InvariantCulture);
 }