FEATURE: Implement Pinterest Provider

[arijitchhatui]

DESTINATION: packages/providers/pinterest

IDEA:

Implement provider for Pinterest - visual discovery and bookmarking platform.

Provider Details

• Provider Type: Media/Content Provider
• Status: Not yet fully implemented
• Priority: Community Contribution

Implementation Requirements

1. Contract Definition - Define extraction interfaces
2. Parser Implementation - Extract metadata from HTML/API
3. Transformer & Pipeline - Process extracted data
4. Provider Class - Main integration point
5. Testing - Comprehensive test coverage

Reference

Follow patterns from existing providers in packages/providers/

See .github/ISSUE_TEMPLATE/provider_implementation_template.md for detailed checklist.