Support byte[] BSON binary and add tests

[mrdevrobot]

• Fix Dispose to also delete WAL sidecar file using DeleteFileIfExists helper
• Fix BinaryProperty_PersistsAcrossReopen cleanup to also delete WAL file
• Fix BinaryProperty_BLiteEngine_WritesBsonBinary_TypedReaderGetsBytes cleanup to also delete WAL file
• Fix IsValidJson to dispose JsonDocument with using var to avoid pooled buffer leaks
• Extract DeleteFileIfExists helper and use it consistently throughout all cleanup code

[Copilot]

Pull request overview

Adds end-to-end support for mapping byte[] properties to BSON Binary in the BLite source generator, with new tests that validate typed/dynamic round-trips and nullable handling.

Changes:

• Extend source generator primitive handling to write/read byte[] as BSON Binary (including nullable cases).
• Exclude byte[] from being treated as a generic collection/array during analysis.
• Add BinaryEntity + BinaryEntities collection and a comprehensive BinaryPropertyTests suite.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/BLite.SourceGenerators/CodeGenerator.cs	Adds byte[] primitive mapping to WriteBinary/ReadBinary and ensures binary reads materialize spans via ToArray().
src/BLite.SourceGenerators/Helpers/SyntaxHelper.cs	Prevents byte[] from being classified as a collection type.
tests/BLite.Shared/MockEntities.cs	Introduces BinaryEntity with required + optional binary fields for testing.
tests/BLite.Shared/TestDbContext.cs	Registers BinaryEntities collection and maps BinaryEntity to binary_entities.
tests/BLite.Tests/BinaryPropertyTests.cs	Adds extensive tests for byte[] persistence, updates, reopen durability, dynamic↔typed compatibility, and JSON caveats.

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[mrdevrobot]

@copilot apply changes based on the comments in this thread

[Copilot]

@copilot apply changes based on the comments in this thread

Applied all four review suggestions in commit a466b22:

• Dispose now deletes the .wal sidecar file via a new DeleteFileIfExists helper
• BinaryProperty_PersistsAcrossReopen and BinaryProperty_BLiteEngine_WritesBsonBinary_TypedReaderGetsBytes both delete the .wal file at cleanup
• All inline File.Exists/File.Delete calls replaced with DeleteFileIfExists for consistency
• IsValidJson now uses using var _ = JsonDocument.Parse(json) to properly dispose the document and avoid pooled buffer leaks