Fix ContainerInterface::has() returning always-true for known services

[mglaman]

Summary

Fixes #668

• Adds drupal.bleedingEdge.containerHasAlwaysTrue parameter (default true in 2.0.x for backwards compat)
• When false (set in bleedingEdge.neon), has() returns bool for found services instead of ConstantBooleanType(true), eliminating false-positive "always true" errors that could cause developers to remove legitimate conditional service guards
• Unknown services still return ConstantBooleanType(false) in both modes
• Will become the default behavior in 2.1.0 by flipping the default in extension.neon

Test plan

• DrupalContainerDynamicReturnTypeTest — asserts 'bool' for known services (bleedingEdge active)
• DrupalContainerDynamicReturnTypeLegacyTest — asserts 'true' for known services (no bleedingEdge, 2.0.x compat)
• php vendor/bin/phpunit --filter="DrupalContainerDynamicReturnType"
• php vendor/bin/phpstan analyze
• php vendor/bin/phpcs

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Adds a configurable switch to control how PHPStan infers the return type of ContainerInterface::has() for known Drupal services, avoiding “always true” false-positives in bleeding-edge mode while keeping 2.0.x compatibility by default.

Changes:

• Introduces drupal.bleedingEdge.containerHasAlwaysTrue (default true), and wires it into the container has() dynamic return type extension.
• Sets the flag to false in bleedingEdge.neon so bleeding-edge mode returns bool (not constant true) for known services.
• Adds/updates type-inference tests and fixtures to cover both the bleeding-edge and legacy behaviors.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/src/Type/data/container.php	Updates assertion for known-service has() to expect bool under bleeding-edge config.
tests/src/Type/data/container-legacy-has.php	Adds legacy-mode fixture asserting known-service has() remains true.
tests/src/Type/DrupalContainerDynamicReturnTypeLegacyTest.php	Adds a dedicated test case running with a “no bleedingEdge” config.
tests/fixtures/config/phpunit-drupal-phpstan-no-bleedingedge.neon	Adds a test config that omits bleedingEdge.neon to validate legacy defaults.
src/Type/ContainerDynamicReturnTypeExtension.php	Implements the new flag: returns BooleanType for known services when enabled.
extension.neon	Adds the new parameter + schema entry, and injects it into the extension service.
bleedingEdge.neon	Flips the new flag to false in bleeding-edge mode.