Add a built-in minimal builder template annotation, e.g. @SimpleMinimalBuilder, that generates the smallest possible builder by disabling all optional features. #257

Motivation

Right now, tests and users that want a "minimal" builder must create a custom template and explicitly disable every optional feature. A dedicated built-in @SimpleMinimalBuilder annotation would make this common use-case a one-liner and give the project a canonical example of a template-based builder preset.

Proposed Solution

Introduce a new public annotation in core:

@SimpleBuilder.Template(options = @SimpleBuilder.Options(
    generateFieldSupplier = OptionState.DISABLED,
    generateFieldConsumer = OptionState.DISABLED,
    generateBuilderConsumer = OptionState.DISABLED,
    generateConditionalHelper = OptionState.DISABLED,
    generateVarArgsHelpers = OptionState.DISABLED,
    generateStringFormatHelpers = OptionState.DISABLED,
    generateAddToCollectionHelpers = OptionState.DISABLED,
    generateUnboxedOptional = OptionState.DISABLED,
    generateWithInterface = OptionState.DISABLED,
    usingArrayListBuilder = OptionState.DISABLED,
    usingArrayListBuilderWithElementBuilders = OptionState.DISABLED,
    usingHashSetBuilder = OptionState.DISABLED,
    usingHashSetBuilderWithElementBuilders = OptionState.DISABLED,
    usingHashMapBuilder = OptionState.DISABLED,
    usingGeneratedAnnotation = OptionState.DISABLED,
    usingBuilderImplementationAnnotation = OptionState.DISABLED,
    usingJacksonDeserializerAnnotation = OptionState.DISABLED,
    generateJacksonModule = OptionState.DISABLED,
    builderSuffix = "MinimalBuilder",
    setterSuffix = ""
))
@Retention(RetentionPolicy.CLASS)
@Target(ElementType.TYPE)
@Inherited
public @interface SimpleMinimalBuilder {}

The exact name can be discussed (SimpleMinimalBuilder, MinimalBuilder, @SimpleBuilder.Minimal, etc.).

Requirements

1. Annotation definition (core/src/main/java/.../SimpleMinimalBuilder.java)

   • Must be implemented purely as a @SimpleBuilder.Template with all optional features disabled.
   • Must be @Inherited so subclasses get a builder too.

2. Dedicated test class (processor/src/test/java/.../SimpleMinimalBuilderTest.java)

   • Follow the pattern of BuilderConfigurationReaderTest.resolveConfiguration_AllLayersTogether_CompleteChain and assert the full generated source for a minimal builder.
   • Cover standalone usage and inheritance from a parent annotated with @SimpleMinimalBuilder.
   • Existing tests that today create ad-hoc "minimal" templates should be migrated to use @SimpleMinimalBuilder where appropriate.

3. Documentation (docs/CONFIGURATION.md)

   • Add a section describing @SimpleMinimalBuilder under ## Template Annotations or a new sub-section.
   • List exactly which features are disabled and why.

4. Example usage (example/src/main/java/...)

   • Add a small DTO annotated with @SimpleMinimalBuilder to demonstrate usage.
   • Ensure the example module builds and its generated output is as expected.

Acceptance Criteria

• @SimpleMinimalBuilder (or chosen name) is available in core.
• It generates only build(), create(), and the field setters — no suppliers, consumers, varargs, collection helpers, with interface, Jackson, or generated annotations.
• New test class validates full generated source for minimal builders.
• Existing minimal-related tests prefer the new annotation.
• Example DTO in example module.
• Documentation updated in docs/CONFIGURATION.md, including link to example builder of example module
• mvn test passes end-to-end.