refactor(configmanager): convert CLI to structured logging with Serilog

Replace Console.WriteLine calls with ILogger usage across all CLI commands.
Serilog is configured via DI with clean message-only output suitable for
CLI tooling. Log levels map to --quiet (Warning), default (Information),
and --verbose (Debug) flags.

- Add Serilog packages and configure in Program.cs
- Convert all 7 command files to use ILoggerFactory from DI
- Add BeginScope with context properties (Command, ConfigPath, etc.)
- Create logging_style.md documenting patterns and best practices
- Update tests with TestLoggingHelper for Serilog test configuration

NEW/tests/Utils/JdeScoping.ConfigManager.Cli.Tests/Commands/PipelineCommandsTests.cs

@@ -24,6 +24,7 @@ public class PipelineCommandsTests
         var services = new ServiceCollection();
         services.AddSingleton(_configFileService);
         services.AddSingleton(_autoDiscoveryService);
+        services.AddTestLogging();
         _serviceProvider = services.BuildServiceProvider();
 
         _configPathOption = new Option<string?>(["--config-path", "-c"]);