#3581133: Automate MR review using PHPCS: disallow `\Drupal::service('something')`, require `\Drupal::service(Something::class)` whenever possible, with automatic fixing

Problem

It's easy to use magic strings like 'entity_type.manager' when calling \Drupal::service() or $this->container->get(). These magic strings:

• defeat static analysis (PHPStan, IDE refactoring)
• are typo-prone with zero compile-time feedback
• obscure the actual type being retrieved

Solution

Add a new PHPCS sniff Canvas.Services.ClassServiceId that:

1. Forbids string-based service IDs:

   // ❌ Forbidden:
   $this->container->get('entity_type.manager')
   \Drupal::service('entity_type.manager')

2. Requires the equivalent ::class constant:

   // ✅ Required:
   $this->container->get(EntityTypeManagerInterface::class)
   \Drupal::service(EntityTypeManagerInterface::class)

3. Auto-fixes violations via phpcbf:

   • Replaces the string with ShortName::class
   • Adds the use import in alphabetical order (respects AlphabeticallySortedUses)
   • Falls back to \Full\Qualified\Name::class on short-name collisions

How it works

The sniff parses *.services.yml files at runtime to build a mapping from string service IDs to their FQCN. It prefers interface aliases (e.g. EntityTypeManagerInterface) over concrete classes (e.g. EntityTypeManager).

Scanned files:

• core/core.services.yml
• core/modules/**/*.services.yml (all core modules and their test modules)
• canvas.services.yml
• modules/**/*.services.yml (all Canvas submodules and their test modules)

Detected patterns:

• $this->container->get('service.id')
• $container->get('service.id')
• \Drupal::service('service.id')

Skipped (no false positives):

• Services with no known FQCN mapping (e.g. kernel, uuid)
• ->get() calls on non-container objects (e.g. $entity->get(...), $config->get(...))
• Strings that already use ::class

Limitations

• Services registered dynamically via ServiceProviderInterface::register() or altered via ServiceModifierInterface::alter() are NOT detected — they don't appear in any *.services.yml file.
• Services from contrib/custom modules outside of Canvas are not scanned. andards/Canvas/ruleset.xml` | Register the new rule |

AI-Generated: Yes

Testing instructions

• CI passes
• Changes made to /src and /tests in MR look reasonable

Closes #3581133