Generator Test Coverage

OneOf4ToIResult Generator (NEW v1.12.0) - ✅ Extension method generation for OneOf - ✅ Intelligent HTTP status mapping - ✅ Error type detection and handling - ✅ Attribute generation
- ✅ Type combinations (ValidationError, NotFoundError, ConflictError, ServerError) - ✅ Conditional generation (no false positives) - ✅ HTTP mapping validation (T1→400, T2→200)

OneOf3ToIResult Generator - ✅ Extension method generation (OneOf3Extensions) - ✅ Attribute generation - ✅ Type combinations (3-way scenarios) - ✅ Conditional generation - ✅ HTTP mapping validation (T1→400, T2→400, T3→200)

ResultToIResult Generator - ✅ Extension method generation - ✅ Attribute generation - ✅ Syntax tree detection - ✅ Conditional generation (zero false positives)

ResultToActionResult Generator (NEW v1.21.0) - ✅ Extension method generation (ToActionResult, ToPostActionResult, etc.) - ✅ Explicit overload generation (onSuccess, onFailure) - ✅ MVC result types (OkObjectResult, CreatedResult, NoContentResult, etc.) - ✅ Attribute generation - ✅ Correct namespace (Generated.ActionResultExtensions) - ✅ Conditional generation (zero false positives) - ✅ Error-free compilation, initialization, and empty compilation handling

OneOfToActionResult Generator (NEW v1.22.0) - ✅ Extension method generation for OneOf → IActionResult - ✅ IError.Tags["HttpStatusCode"] tag-based mapping (Phase 1) - ✅ Type-name heuristic fallback (Phase 2) - ✅ MVC result types (OkObjectResult, NotFoundObjectResult, ConflictObjectResult, etc.) - ✅ Attribute generation per arity (2/3/4) - ✅ Correct namespace (Generated.OneOfActionResultExtensions) - ✅ Conditional generation (zero false positives)