v0.1.0 of pp_ocr

Flutter plugin for offline OCR using PP-OCRv6 (PaddleOCR) with ONNX Runtime C++ inference. Supports text detection and recognition on Windows. Changelog excerpt: - Initial release. - Offline OCR using PaddleOCR PP-OCRv6 models with ONNX Runtime. - Text detection (DB) and recognition (CRNN+CTC) pipeline. - Unicode file path support on Windows (Chinese, Japanese, etc.). - Detection box overlay with recognized text and confidence scores. - Debug logging with UTF-8 validation utilities.