feat(phase1): implement OpenCV image processing pipeline

- Create ImageProcessor service with EXIF orientation detection
- Implement smart cropping via OpenCV contour detection (10% padding)
- Add text orientation detection using Hough line transform
- Resize and compress images to 1200px with 85% JPEG quality
- Generate 200px square thumbnails with center crop
- Fallback to Pillow if OpenCV fails
- Comprehensive test suite: 28 tests all passing
- File size validation (reject >10MB)
- Graceful error handling for corrupted/invalid images
- Update requirements.txt with opencv-python, piexif, python-magic

venv/lib/python3.12/site-packages/numpy/version.pyi

@@ -0,0 +1,9 @@
+from typing import Final, LiteralString
+
+version: Final[LiteralString] = ...
+__version__: Final[LiteralString] = ...
+full_version: Final[LiteralString] = ...
+
+git_revision: Final[LiteralString] = ...
+release: Final[bool] = ...
+short_version: Final[LiteralString] = ...