docs: align documentation with implemented API

[Copilot]

Documentation was missing several implemented methods and had incomplete type definitions that didn't match the code.

API Reference Updates

• Added rotation/flip methods: rotate(), rotate90(), rotate180(), rotate270(), flipHorizontal(), flipVertical()
• Added metadata methods: Image.getSupportedMetadata(), Image.extractMetadata()
• Updated ResizeOptions to include bicubic method and fit/cover/contain modes
• Completed TIFFEncodeOptions with grayscale and rgb options

Processing & Examples

• Added rotation/flipping section with EXIF orientation correction examples
• Enhanced resize documentation with fit modes and bicubic interpolation
• Added practical examples: kaleidoscope effect, aspect-ratio preserving resize

Example

// Fit mode now documented
image.resize({ width: 800, height: 600, fit: "cover" });

// Rotation methods now documented
image.rotate(90).flipHorizontal();

// EXIF orientation correction
if (image.metadata?.orientation === 6) image.rotate90();

Code Analysis

Reviewed test file structure - test/rotation_flip.test.ts (integration) and test/utils/rotation_flip.test.ts (unit) serve distinct purposes. No deduplication needed.

Original prompt

Review project with focus on code deduplication, consistent api and consistency between docs/ readme and actual code.

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.