v1.0.0

release: v1.0.0 - Python Blossom client with comprehensive BUD support

- Restructure project to PEP 517 standard layout (src/python_blossom/)
- Implement comprehensive private/public key normalization (nsec/npub format support)
- Standardize all parameter naming for consistency (pubkey parameter)
- Add BlossomClient with 9 implemented BUDs and full NIP-98 authorization support
- Implement Blossom protocol endpoints: retrieval, upload, list, delete, mirror, media
- Add Nostr integration for server list publishing (kind 10063, BUD-03)
- Complete test suite with 51 passing tests across 12 test files
- Add 10 example scripts demonstrating all supported endpoints
- Document unsupported endpoints (BUD-09) for future implementation
- Fix test infrastructure and server capability detection
- Configure Pipenv with Python 3.11 and all dependencies