build: Add PyPI package deployment support

Complete package deployment configuration for PyPI publishing:

- Add MANIFEST.in to control package distribution
  - Include LICENSE, README, requirements files
  - Include docs/ and examples/ directories
  - Include type stub marker (py.typed)
  - Exclude test files and development artifacts

- Fix dependency specification
  - Add pydantic[email] for email validation support
  - Required for User model EmailStr fields
  - Update both requirements.txt and pyproject.toml

- Create comprehensive deployment documentation
  - docs/deployment.md - Complete PyPI publishing guide
    - Pre-deployment checklist
    - Build and test procedures
    - PyPI upload instructions
    - Troubleshooting guide
    - CI/CD automation examples
  - DEPLOYMENT_READY.md - Deployment status summary
    - What's included in distributions
    - Verification test results
    - Quick deployment steps
    - PyPI vs Gitea comparison

Package is now 100% ready for PyPI deployment:
✅ Builds successfully (sdist + wheel)
✅ Installs correctly with all dependencies
✅ Imports work without errors
✅ All files properly included
✅ Complete documentation provided

Testing:
- Successfully built wikijs_python_sdk-0.1.0.tar.gz (134 KB)
- Successfully built wikijs_python_sdk-0.1.0-py3-none-any.whl (66 KB)
- Verified installation and imports work correctly
- All dependencies resolve properly

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

MANIFEST.in

@@ -0,0 +1,28 @@
+# Include documentation and license
+include README.md
+include LICENSE
+include requirements.txt
+include requirements-dev.txt
+
+# Include all documentation
+recursive-include docs *.md
+recursive-include docs *.rst
+
+# Include examples
+recursive-include examples *.py
+recursive-include examples *.md
+
+# Include type stubs
+recursive-include wikijs py.typed
+
+# Exclude development and build files
+exclude .gitignore
+exclude .pre-commit-config.yaml
+exclude CLAUDE.md
+exclude working_playground.py
+recursive-exclude tests *
+recursive-exclude .github *
+recursive-exclude .gitea *
+recursive-exclude * __pycache__
+recursive-exclude * *.py[co]
+recursive-exclude * .DS_Store