Change CLI flag LogLevel to log-level

[RubenCerna2079]

Why make this change?

• This solves issue [Bug]: --LogLevel should be --loglevel (and case insensitive) like all the other CLI flags #3257

What is this change?

We changed the dab start --LogLevel flag to --log-level in order to have it follow the conventions we already have. We also allow for the CLI to still use the previous --LogLevel flag but add a warning sign to ensure the user knows it is deprecated. Lastly, also changed all of the comments that mention the previous --LogLevel and updated it to use the new --log-level.

How was this tested?

• Integration Tests
• Unit Tests
  Changed the tests that were for --LogLevel so they now use --log-level and added a few extra cases to ensure the --LogLevel flag still works

Sample Request(s)

dab start --log-level information
dab start --LogLevel warning

[Copilot]

Pull request overview

This PR updates the dab start CLI flag for engine log level from --LogLevel to the convention-aligned --log-level, while keeping --LogLevel as a hidden legacy alias and updating related comments/tests across CLI, Service, and MCP components.

Changes:

• Rename CLI option from --LogLevel to --log-level (with legacy alias retained).
• Update CLI-to-Service argument forwarding to emit --log-level and add a deprecation warning for --LogLevel.
• Update comments and unit/e2e tests to reference --log-level, including MCP log-level precedence documentation.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/Service/Startup.cs	Updates inline comments to reference --log-level.
src/Service/Program.cs	Updates service-side log-level extraction to look for --log-level.
src/Service.Tests/UnitTests/DynamicLogLevelProviderTests.cs	Updates test comments to reference --log-level.
src/Core/Telemetry/ILogLevelController.cs	Updates interface documentation to reference --log-level.
src/Cli/Utils.cs	Updates CLI documentation strings to reference --log-level.
src/Cli/Program.cs	Updates early-flag scan to recognize --log-level.
src/Cli/Exporter.cs	Updates StartOptions construction to include new legacy parameter.
src/Cli/CustomLoggerProvider.cs	Updates comments to reference --log-level behavior in MCP mode.
src/Cli/ConfigGenerator.cs	Adds legacy handling/deprecation warning and forwards --log-level to the service.
src/Cli/Commands/StartOptions.cs	Adds --log-level option and hidden legacy --LogLevel option.
src/Cli.Tests/EndToEndTests.cs	Updates e2e coverage to use --log-level and adds legacy cases.
src/Cli.Tests/CustomLoggerTests.cs	Updates test docs to reference --log-level.
src/Azure.DataApiBuilder.Mcp/Core/McpStdioServer.cs	Updates MCP docs/comments to reference --log-level.

Comments suppressed due to low confidence (1)

src/Cli/Program.cs:67

• ParseEarlyFlags only recognizes the new "--log-level" flag. When users pass the legacy "--LogLevel" (which this PR still supports), MCP stdio logging behavior will be wrong because Utils.IsCliOverriding/CliLogLevel won’t be set before logger creation (leading to suppressed stderr output in MCP mode).

                if (string.Equals(arg, "--mcp-stdio", StringComparison.OrdinalIgnoreCase))
                {
                    Utils.IsMcpStdioMode = true;
                }
                else if (string.Equals(arg, "--log-level", StringComparison.OrdinalIgnoreCase) && i + 1 < args.Length)
                {
                    Utils.IsCliOverriding = true;
                    if (Enum.TryParse<LogLevel>(args[i + 1], ignoreCase: true, out LogLevel cliLogLevel))
                    {