Replace Flat hydrator with PrestyledAssoc for alias-keyed rows

[alganet]

PrestyledAssoc hydrates associative rows whose keys follow the specifier__styledProp convention, grouping by prefix and mapping directly to entities. This eliminates the reverse-iteration, boundary detection, and entity-stack machinery from the old Flat hydrator.

Also adds EntityFactory::enumerateFields() for DB-column-to-property mapping, a styled flag on set() to skip redundant style conversion, and Composite::COMPOSITION_MARKER to centralize the join-alias prefix.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.23%. Comparing base (bc63e1e) to head (8b5503a).

Additional details and impacted files

@@             Coverage Diff              @@
##             master      #26      +/-   ##
============================================
- Coverage     98.39%   98.23%   -0.16%     
- Complexity      294      300       +6     
============================================
  Files            17       17              
  Lines           622      624       +2     
============================================
+ Hits            612      613       +1     
- Misses           10       11       +1     

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[Copilot]

Pull request overview

This PR replaces the previous “flat row” hydrator with a new PrestyledAssoc hydrator that consumes alias-keyed associative rows (specifier__styledProp) and simplifies multi-entity hydration, while also adding supporting EntityFactory utilities and composite alias constants.

Changes:

• Add PrestyledAssoc hydrator and corresponding PHPUnit coverage; remove Flat hydrator and its tests.
• Extend EntityFactory with enumerateFields() and a styled flag on set() to support pre-styled hydration.
• Introduce Composite::COMPOSITION_MARKER to centralize composition alias naming.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/Hydrators/PrestyledAssoc.php	New hydrator that groups alias-keyed columns by prefix and hydrates entities directly.
tests/Hydrators/PrestyledAssocTest.php	New tests covering basic hydration, typing, composites, caching, and unknown prefixes.
src/Hydrators/Flat.php	Removed legacy flat-row hydrator implementation.
tests/Hydrators/FlatTest.php	Removed tests for legacy flat-row hydrator.
src/EntityFactory.php	Adds enumerateFields() and set(..., styled: bool) optimization for pre-styled props.
tests/EntityFactoryTest.php	Adds tests for enumerateFields() and set(..., styled: true).
src/Collections/Composite.php	Adds a constant for composition alias marker used by hydration.

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