refactor: replace Console.WriteLine with DiagnosticLog service

Replace 495+ Console.WriteLine debug statements across handlers, dispatching, services, views, and window components with centralized DiagnosticLog service for proper logging infrastructure. Add new DiagnosticLog.cs service with Debug/Error methods to eliminate debug logging pollution in production code.

Services/DiagnosticLog.cs

@@ -0,0 +1,80 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Diagnostics;
+
+namespace Microsoft.Maui.Platform.Linux.Services;
+
+/// <summary>
+/// Centralized diagnostic logging for the Linux MAUI platform.
+/// Logging is enabled only in DEBUG builds by default, or when
+/// explicitly enabled via <see cref="IsEnabled"/>.
+/// </summary>
+public static class DiagnosticLog
+{
+    private static bool? _isEnabled;
+
+    /// <summary>
+    /// Gets or sets whether diagnostic logging is enabled.
+    /// Defaults to true in DEBUG builds, false in RELEASE builds.
+    /// </summary>
+    public static bool IsEnabled
+    {
+        get
+        {
+            if (_isEnabled.HasValue)
+                return _isEnabled.Value;
+#if DEBUG
+            return true;
+#else
+            return false;
+#endif
+        }
+        set => _isEnabled = value;
+    }
+
+    /// <summary>
+    /// Logs an informational diagnostic message.
+    /// </summary>
+    [Conditional("DEBUG")]
+    public static void Debug(string tag, string message)
+    {
+        if (IsEnabled)
+            System.Console.WriteLine($"[{tag}] {message}");
+    }
+
+    /// <summary>
+    /// Logs an informational diagnostic message (always writes when enabled, not conditional on DEBUG).
+    /// Use for important operational messages that should appear in release builds when logging is enabled.
+    /// </summary>
+    public static void Info(string tag, string message)
+    {
+        if (IsEnabled)
+            System.Console.WriteLine($"[{tag}] {message}");
+    }
+
+    /// <summary>
+    /// Logs a warning message. Always writes when logging is enabled.
+    /// </summary>
+    public static void Warn(string tag, string message)
+    {
+        if (IsEnabled)
+            System.Console.Error.WriteLine($"[{tag}] WARNING: {message}");
+    }
+
+    /// <summary>
+    /// Logs an error message. Always writes regardless of IsEnabled.
+    /// </summary>
+    public static void Error(string tag, string message)
+    {
+        System.Console.Error.WriteLine($"[{tag}] ERROR: {message}");
+    }
+
+    /// <summary>
+    /// Logs an error message with exception details. Always writes regardless of IsEnabled.
+    /// </summary>
+    public static void Error(string tag, string message, Exception ex)
+    {
+        System.Console.Error.WriteLine($"[{tag}] ERROR: {message}: {ex.Message}");
+    }
+}