Missing support for project-level auth.json

[kasparsd]

Describe the bug

The documentation states that Satis supports project-level auth.json files:

satis/docs/using.md

Lines 215 to 217 in 2499574

	The storage can be done either globally in the `COMPOSER_HOME/auth.json` file
	(`COMPOSER_HOME` defaults to `~/.composer` or `%APPDATA%/Composer` on Windows)
	or also in the project directory directly sitting besides your composer.json.

However, the current source code only supports global auth.json and doesn't use the project-level auth.json at all:

satis/src/Console/Command/BuildCommand.php

Lines 283 to 287 in 2499574

	// load global auth file
	$file = new JsonFile($config->get('home') . '/auth.json');
	if ($file->exists()) {
	$config->merge(['config' => $file->read()]);
	}

To Reproduce

1. Create a new project and require satis as a dependency in composer.json:

    {
        "name": "example/satis-example",
        "type": "project",
        "require": {
            "composer/satis": "^1.0"
        }
    }
   

2. Add satis.json with a non-existent GitHub project repository (doesn't need to exist for this test):

    {
        "name": "satis/example",
        "homepage": "http://satis.example.com",
        "repositories": [
            { "type": "vcs", "url": "https://github.com/mycompany/privaterepo" }
        ],
        "archive": {
            "directory": "dist"
        },
        "require-all": true
    }
   

3. Add auth.json to the current project directory by running composer config github-oauth.github.com token123 (doesn't have to be a valid token).

4. Run the build vendor/bin/satis build -vvv -n satis.json public to produce the build and notice how it doesn't use the configured token:

Checked CA file /opt/homebrew/etc/ca-certificates/cert.pem: valid
Executing command (/path/to/project/satis-example): git branch -a --no-color --no-abbrev -v
Executing command (/path/to/project/satis-example): git describe --exact-match --tags
Executing command (CWD): git --version
Executing command (/path/to/project/satis-example): git log --pretty="%H" -n1 HEAD --no-show-signature
Executing command (/path/to/project/satis-example): hg branch
Executing command (/path/to/project/satis-example): fossil branch list
Executing command (/path/to/project/satis-example): fossil tag list
Executing command (/path/to/project/satis-example): svn info --xml
Failed to initialize global composer: Composer could not find the config file: /Users/kaspars/.composer/composer.json
To initialize a project, please create a composer.json file as described in the https://getcomposer.org/ "Getting Started" section
Reading /path/to/project/satis-example/vendor/composer/installed.json
Scanning packages
Downloading https://api.github.com/repos/mycompany/privaterepo
Executing command (CWD): git config github.accesstoken
Executing command (CWD): git clone --mirror -- 'git@github.com:mycompany/privaterepo.git' '/Users/kaspars/.composer/cache/vcs/git-github.com-mycompany-privaterepo.git/'
Executing command (CWD): git config github.accesstoken
Executing command (CWD): git --version
Failed to clone the git@github.com:mycompany/privaterepo.git repository, try running in interactive mode so that you can enter your GitHub credentials

In Git.php line 404:
                                                                                                                                                     
  [RuntimeException]                                                                                                                                 
  Failed to execute git clone --mirror -- 'git@github.com:mycompany/privaterepo.git' '/Users/kaspars/.composer/cache/vcs/git-github.com-mycompany-p  
  rivaterepo.git/'                                                                                                                                   
                                                                                                                                                     
  Cloning into bare repository '/Users/kaspars/.composer/cache/vcs/git-github.com-mycompany-privaterepo.git'...                                      
  ERROR: Repository not found.                                                                                                                       
  fatal: Could not read from remote repository.                                                                                                      
                                                                                                                                                     
  Please make sure you have the correct access rights                                                                                                
  and the repository exists.   

Outcome

See above ☝️.

The $config->get('home') . '/auth.json' path points to the global Composer home directory so the local project-level auth.json isn't checked.

Expected behavior

Satis uses the auth.json data from the project root directory.

Additional context

None.