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>

pyproject.toml

@@ -26,7 +26,7 @@ classifiers = [
 ]
 dependencies = [
     "requests>=2.28.0",
-    "pydantic>=1.10.0",
+    "pydantic[email]>=1.10.0",
     "typing-extensions>=4.0.0",
 ]
 dynamic = ["version"]