feat: add opt-out for JsonPropertyName attributes

[geirsagberg-udir]

Summary

• Adds GenerateJsonPropertyNameAttributes option (default true) to GeneratorOptions so [JsonPropertyName] emission can be suppressed.
• Exposes the toggle through the CLI as --no-json-property-name-attributes.
• Useful when the consuming serializer already applies the desired naming policy and the attributes would just be noise.

Test plan

• CSharpCodeEmitterTests covers the opt-out path
• CSharpSchemaGeneratorTests verifies generated output omits the attribute when disabled
• GeneratorOptionsTests confirms the default remains true (no behavior change for existing users)

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Replaces #45 — re-opened from a dedicated feature branch so my fork's main can track upstream cleanly.

[geirsagberg-udir]

full disclosure: Coded by Claude, but I verified it works manually by compiling and running the tool on our own spec

[Copilot]

Pull request overview

Adds a new generator option to suppress emitting System.Text.Json.Serialization.JsonPropertyName attributes, with corresponding CLI/docs updates, to support consumers that rely on serializer naming policies instead of per-property attributes.

Changes:

• Added GeneratorOptions.GenerateJsonPropertyNameAttributes (default true) to control [JsonPropertyName] emission.
• Wired the option through the CLI via --no-json-property-name-attributes and updated help text / docs.
• Added unit + integration tests covering the opt-out behavior and confirming the default remains enabled.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/OpenApiCodeGenerator.Tests/GeneratorOptionsTests.cs	Asserts the new option defaults to true.
tests/OpenApiCodeGenerator.Tests/CSharpSchemaGeneratorTests.cs	Integration coverage ensuring generated code omits [JsonPropertyName] and serializes correctly with a naming policy when disabled.
tests/OpenApiCodeGenerator.Tests/CSharpCodeEmitterTests.cs	Unit coverage ensuring emitter skips property attributes when disabled.
src/OpenApiCodeGenerator/GeneratorOptions.cs	Introduces GenerateJsonPropertyNameAttributes option with docs and default.
src/OpenApiCodeGenerator/CSharpCodeEmitter.cs	Gates [JsonPropertyName] emission behind the new option.
src/OpenApiCodeGenerator.Cli/Program.cs	Adds --no-json-property-name-attributes flag and passes it into GeneratorOptions.
docs/src/content/docs/reference/cli.md	Documents the new CLI flag and adds it to examples.
docs/src/content/docs/guides/configuration.md	Documents the library option + CLI mapping, plus guidance and examples.
README.md	Updates CLI options list to include the new flag.

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[geirsagberg-udir]

fixed merge conflicts

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 4 comments.

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[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

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