Phase 5: CritterMapper implementation

[evanchooly]

Summary

• Implements CritterMapper extends AbstractMapper with three-tier entity model discovery
• Tier 1: loads pre-generated model from classpath by naming convention (critter-maven AOT)
• Tier 2: generates model at runtime via CritterGizmoGenerator (Gizmo + VarHandle)
• Tier 3: falls back to reflection-based EntityModel
• copy() shares immutable CritterEntityModel references; clones reflective fallback models
• Per-type fallback logging via ConcurrentHashMap.newKeySet() (logs once, not on every access)
• synchronized mapEntity prevents concurrent duplicate-discriminator race condition

Closes #4187

Test plan

• TestCritterMapper — 8 tests: runtime generation, collection name, caching, copy semantics, concurrent access, null/non-entity inputs
• Full morphia-core suite — 1,231 tests, zero failures

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Implements the new CritterMapper and wires it into Morphia so users can select critter-based bytecode model generation (with reflection fallback) via configuration.

Changes:

• Add CritterMapper (three-tier discovery: pre-generated → runtime generation → reflection) and integrate it into MorphiaDatastore’s mapper selection.
• Rename the reflection mapper type from LEGACY to REFLECTION and update defaults/docs accordingly.
• Add/adjust tests covering critter mapper behavior (runtime generation, caching, copy semantics, concurrency) and integration config.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
docs/modules/ROOT/examples/complete-morphia-config.properties	Updates example config defaults/values for the mapper selection.
critter/critter-integration-tests/src/test/java/dev/morphia/critter/CritterCrudTest.java	Forces critter mapper usage in integration CRUD test setup.
core/src/test/java/dev/morphia/mapping/TestCritterMapper.java	Adds a dedicated test suite for CritterMapper behavior and concurrency.
core/src/test/java/dev/morphia/mapping/CritterMapperTestEntity.java	Adds a simple @Entity used by critter mapper tests.
core/src/main/java/dev/morphia/mapping/MapperType.java	Renames the reflection mapper enum constant and keeps CRITTER option.
core/src/main/java/dev/morphia/mapping/CritterMapper.java	Introduces the new hybrid mapper with three-tier discovery + copy semantics.
core/src/main/java/dev/morphia/mapping/AbstractMapper.java	Renames the stored classloader field and uses it for package scanning.
core/src/main/java/dev/morphia/critter/CritterClassLoader.java	Marks CritterClassLoader as internal/hidden.
core/src/main/java/dev/morphia/config/converters/PropertyAnnotationProviderConverter.java	Changes property-annotation-provider conversion behavior.
core/src/main/java/dev/morphia/config/MorphiaConfig.java	Updates mapper default to reflection and documents the new enum constant.
core/src/main/java/dev/morphia/config/ManualMorphiaConfig.java	Updates default mapper type and adjusts constructor visibility/annotations.
core/src/main/java/dev/morphia/MorphiaDatastore.java	Enables MapperType.CRITTER to instantiate CritterMapper.

[evanchooly]

Code review

Found 1 issue:

1. sofia.properties has a dead message that references the now-renamed LEGACY enum value. Sofia.mapperNotYetAvailable is no longer called anywhere — MorphiaDatastore.createMapper() no longer throws it now that CritterMapper is wired up. The message also tells users to set morphia.mapper=legacy, which is no longer a valid value (renamed to reflection in this PR).

morphia/core/src/main/resources/sofia.properties

Lines 32 to 34 in 1fae66c

	instantiation.problem=Can''t instantiate the type {0}: {1}
	mapper.not.yet.available={0} mapper is not yet available. Set morphia.mapper=legacy in your configuration.
	invalid.bson.operation=Value expected to be of type {0} is of unexpected type {1}

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