feat: add the EnvironmentDetector utility class and environment service

[paulbalandan]

Description
This PR adds the EnvironmentDetector utility class as a simple mockable wrapper to accessing the ENVIRONMENT constant, allowing us to test previously unreachable code branches dependent on the current environment.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value (without duplication)
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[michalsn]

I think it's a good change.

I added some suggestions to the phpdocs / user guide.

[neznaika0]

LGTM

[michalsn]

envdetector is shorter, but it reads like ".env detector" or "environment variables detector", which is a different concept in this codebase.

Why not just use environment? It's the most natural read: service('environment')->isProduction().

It's also aligned with the code we used to write: ENVIRONMENT === 'production'.

[neznaika0]

I have already said my opinion - for the environment, this can already be attributed to the DotEnv loader. Since the comparison with a constant looks clear, and the service is associated with all the features of $_ENV.

The last word belongs to the members, I have less importance here.

[michalsn]

In this context, "environment" means the current CI runtime mode (development, production, testing), not DotEnv or general $_ENV handling.

DotEnv is about loading environment variables, while this service is only about checking the current application environment in a mockable way. Those are related concepts, but not the same responsibility.

[neznaika0]

@michalsn thanks for the clarification. I know this, and I can always see what the code is doing in the system.

It's more about the other participants. You can see the questions in the Issue/Forum ‐ someone mistakenly perceives the specifics of the framework or expects precise actions in the documentation (although everything looks clear to us).

[michalsn]

I see your point, but I don't find environment misleading. To me, envdetector actually sounds more like something related to .env detection.

[michalsn]

Thanks, looks good.

[paulbalandan]

Thanks all for the reviews!