Make CLI Log Labels consistent with ASP.NET Core and use appropriate label on startup (#3307)

## Why make this change?

Closes #3269

## What is this change?

Align the CLI logger labels with the labels used in ASP.Net Core.
Downgraded internal plumbing message from `Information` to `Debug`

Add a test case to cover the changed behavior.

## How was this tested?

Added a test case to validate the new behavior.

Author: aaronburtle

src/Cli.Tests/CustomLoggerTests.cs

@@ -0,0 +1,49 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+namespace Cli.Tests;
+
+/// <summary>
+/// Tests for CustomLoggerProvider and CustomConsoleLogger, verifying
+/// that log level labels use ASP.NET Core abbreviated format.
+/// </summary>
+[TestClass]
+public class CustomLoggerTests
+{
+    /// <summary>
+    /// Validates that each enabled log level produces the correct abbreviated label
+    /// matching ASP.NET Core's default console formatter convention.
+    /// Trace and Debug are below the logger's minimum level and produce no output.
+    /// </summary>
+    [DataTestMethod]
+    [DataRow(LogLevel.Information, "info:")]
+    [DataRow(LogLevel.Warning, "warn:")]
+    [DataRow(LogLevel.Error, "fail:")]
+    [DataRow(LogLevel.Critical, "crit:")]
+    public void LogOutput_UsesAbbreviatedLogLevelLabels(LogLevel logLevel, string expectedPrefix)
+    {
+        CustomLoggerProvider provider = new();
+        ILogger logger = provider.CreateLogger("TestCategory");
+
+        TextWriter originalOut = Console.Out;
+        try
+        {
+            StringWriter writer = new();
+            Console.SetOut(writer);
+
+            logger.Log(logLevel, "test message");
+
+            string output = writer.ToString();
+            Assert.IsTrue(
+                output.StartsWith(expectedPrefix),
+                $"Expected output to start with '{expectedPrefix}' but got: '{output}'");
+            Assert.IsTrue(
+                output.Contains("test message"),
+                $"Expected output to contain 'test message' but got: '{output}'");
+        }
+        finally
+        {
+            Console.SetOut(originalOut);
+        }
+    }
+}

src/Cli/CustomLoggerProvider.cs

@@ -56,6 +56,19 @@ public class CustomConsoleLogger : ILogger
             {LogLevel.Critical, ConsoleColor.DarkRed}
         };
 
+        /// <summary>
+        /// Maps LogLevel to abbreviated labels matching ASP.NET Core's default console formatter.
+        /// </summary>
+        private static readonly Dictionary<LogLevel, string> _logLevelToAbbreviation = new()
+        {
+            {LogLevel.Trace, "trce"},
+            {LogLevel.Debug, "dbug"},
+            {LogLevel.Information, "info"},
+            {LogLevel.Warning, "warn"},
+            {LogLevel.Error, "fail"},
+            {LogLevel.Critical, "crit"}
+        };
+
         /// <summary>
         /// Creates Log message by setting console message color based on LogLevel.
         /// </summary>
@@ -66,11 +79,16 @@ public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Except
                 return;
             }
 
+            if (!_logLevelToAbbreviation.TryGetValue(logLevel, out string? abbreviation))
+            {
+                return;
+            }
+
             ConsoleColor originalForeGroundColor = Console.ForegroundColor;
             ConsoleColor originalBackGroundColor = Console.BackgroundColor;
-            Console.ForegroundColor = _logLevelToForeGroundConsoleColorMap[logLevel];
-            Console.BackgroundColor = _logLevelToBackGroundConsoleColorMap[logLevel];
-            Console.Write($"{logLevel}:");
+            Console.ForegroundColor = _logLevelToForeGroundConsoleColorMap.GetValueOrDefault(logLevel, ConsoleColor.White);
+            Console.BackgroundColor = _logLevelToBackGroundConsoleColorMap.GetValueOrDefault(logLevel, ConsoleColor.Black);
+            Console.Write($"{abbreviation}:");
             Console.ForegroundColor = originalForeGroundColor;
             Console.BackgroundColor = originalBackGroundColor;
             Console.WriteLine($" {formatter(state, exception)}");

src/Service/Startup.cs

@@ -600,7 +600,7 @@ private void ConfigureResponseCompression(IServiceCollection services, RuntimeCo
                 options.Level = systemCompressionLevel;
             });
 
-            _logger.LogInformation("Response compression enabled with level '{compressionLevel}' for REST, GraphQL, and MCP endpoints.", compressionLevel);
+            _logger.LogDebug("Response compression enabled with level '{compressionLevel}' for REST, GraphQL, and MCP endpoints.", compressionLevel);
         }
 
         /// <summary>