Implemented the ValidatePDF feature end-to-end:
- Added `/api/v1/documents/validate` Minimal API endpoint.
- Introduced centralized ExceptionHandlingMiddleware.
- Configured Swagger with `AddSwaggerDocumentation` extension.
- Enabled XML comments in `DocumentOperator.API.csproj`.
- Updated DTOs with XML comments and added `FileSizeMB`.
- Added integration tests for the ValidatePDF endpoint (3 tests).
- Registered infrastructure services (e.g., `IPdfProcessor`).
- Refactored `Program.cs` to include middleware and endpoints.
- Updated PHASENPLAN.md and ROADMAP.md to reflect progress.
- Cleaned up code and made `Program` accessible for tests.
Restructured project files across all layers:
- Removed `Controllers` folder reference from `DocumentOperator.API.csproj`.
- Added folder structure to `DocumentOperator.Application`, `DocumentOperator.Domain`, and `DocumentOperator.Infrastructure` projects for better organization.
Introduced new API configurations and middleware:
- Added `SerilogConfiguration` and `SwaggerConfiguration` classes.
- Added `ExceptionHandlingMiddleware`, `RequestLoggingMiddleware`, and `TenantResolutionMiddleware`.
Implemented new document processing feature:
- Added `ProcessDocumentCommand`, `ProcessDocumentHandler`, and `ProcessDocumentValidator` classes in the application layer.
