fix(apt): detect cycles through createDefaultVariable=false entities

[o54711254]

Background

Follow-up to @velo's review on #1905.

Closes #1949.

AbstractQuerydslProcessor.detectCircularQClassReferences previously filtered context.entityTypes by createDefaultVariable() before passing the map to QClassCycleDetector.

Because the detector resolves neighbors through that map, removing an entity also removes the reference paths through it. However, createDefaultVariable controls static default instance generation; it does not remove constructor references to other Q-classes.

As a result, a cycle passing through a createDefaultVariable=false entity could go undetected even when the remaining static default instances could cause a class initialization deadlock.

Changes

• Traverse the full context.entityTypes map without filtering out intermediate entities.
• Return List<List<EntityType>> from QClassCycleDetector.detect so the processor can check each entity's configuration after detection.
• Report a detected cycle only when at least two distinct entities have createDefaultVariable() == true.
• Use .distinct() to avoid counting the repeated endpoint twice.
• Keep the existing DFS traversal and warning format.

The two-entity threshold follows the reasoning in the #1905 review: with only one static default instance, the circular initialization re-entry occurs on the same thread, which JVM class initialization permits.

Tests

• Adapt QClassCycleDetectorTest to the new return type while preserving existing graph assertions.
• Verify that a three-entity cycle produces a warning when the middle entity has @Config(createDefaultVariable = false).
• Verify that a bidirectional pair produces no warning when static default instances are disabled globally.
• Verify that a bidirectional pair produces no warning when only one entity generates a static default instance.
• Assert that the warning includes -Aquerydsl.createDefaultVariable=false.
• Retain the existing self-reference suppression tests.

[velo]

LGTM. Traversing the full entity graph and filtering the detected cycles afterwards fixes the missed cycles through createDefaultVariable=false nodes, and the >=2 threshold matches the re-entrant class-init reasoning from #1905. The detector is package-private, so there is no API impact. Good test coverage. Thanks!