Extract hydration from Relational into AbstractMapper

[alganet]

• Add resolveEntityName() to Collection with polymorphic override in Typed that reads the discriminator column via EntityFactory
• Move Filtered persist delegation to AbstractMapper::persist(), so any backend routes filtered collections to their parent automatically
• Move postHydrate()/tryHydration() to AbstractMapper as protected methods for FK-to-object wiring using Style naming conventions
• Move buildEntitiesInstances() to AbstractMapper for collection-tree entity creation with Filtered skip and Composite duplication
• Rewrite InMemoryMapper to use shared postHydrate() instead of custom resolveRelations(), proving the abstraction works outside SQL
• InMemoryMapper now supports Typed collections via resolveEntityName()
• Remove unnecessary local variable aliases for $this->entityFactory

[Copilot]

Pull request overview

This PR refactors entity hydration and related-entity wiring into AbstractMapper, adds a per-row entity-name resolution hook on Collection (with a polymorphic override in Typed), and updates the in-memory test mapper to consume the shared hydration logic.

Changes:

• Add Collection::resolveEntityName() and override it in Collections\Typed using a discriminator column read via EntityFactory.
• Move hydration wiring logic into AbstractMapper (postHydrate() / tryHydration()) and update InMemoryMapper to use it.
• Add Filtered persist delegation in AbstractMapper::persist() and introduce buildEntitiesInstances() as a shared helper.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
tests/InMemoryMapper.php	Refactors relation fetching to build an entity graph + call shared postHydrate(), and uses resolveEntityName() for Typed collections.
src/Collections/Typed.php	Implements discriminator-based entity resolution via resolveEntityName().
src/Collections/Collection.php	Introduces the resolveEntityName() extension point on all collections.
src/AbstractMapper.php	Adds Filtered persist routing, shared hydration wiring helpers, and shared entity-instance building helper.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

You can also share your feedback on Copilot code review. Take the survey.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 61.53846% with 15 lines in your changes missing coverage. Please review.
✅ Project coverage is 96.13%. Comparing base (f86f395) to head (b8b3f69).
⚠️ Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
src/AbstractMapper.php	61.76%	13 Missing ⚠️
src/Collections/Collection.php	0.00%	2 Missing ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##              master      #14      +/-   ##
=============================================
- Coverage     100.00%   96.13%   -3.87%     
- Complexity       138      157      +19     
=============================================
  Files             13       13              
  Lines            349      388      +39     
=============================================
+ Hits             349      373      +24     
- Misses             0       15      +15     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.