Refactor into integrated Python package structure

Architecture Changes:
- Created src/seo/ package with modular architecture
- Main application class (SEOApp) with Rails-inspired API
- Separated concerns into distinct modules:
  - app.py: Main application orchestrator
  - cli.py: Command-line interface
  - config.py: Configuration management
  - exporter.py: Post export functionality
  - analyzer.py: AI analysis
  - recategorizer.py: Recategorization
  - seo_checker.py: SEO quality checking
  - categories.py: Category management
  - approval.py: User approval system

New Features:
- Proper Python package structure (src layout)
- setup.py and setup.cfg for installation
- Can be installed with: pip install -e .
- Entry point: seo = seo.cli:main
- Cleaner imports and dependencies

Benefits:
- Better code organization
- Easier to maintain and extend
- Follows Python best practices
- Proper package isolation
- Can be imported as library
- Testable components
- Clear separation of concerns

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

README.md

@@ -193,23 +193,39 @@ The SEO automation tool provides a simple, intuitive CLI inspired by Ruby on Rai
 
 ```
 seo/
-├── seo                          # Main CLI application (executable)
-├── scripts/
-│   ├── config.py                # Configuration loader
-│   ├── export_posts_for_ai_decision.py
-│   ├── ai_analyze_posts_for_decisions.py
-│   ├── multi_site_seo_analyzer.py
-│   ├── category_manager.py      # Category management
-│   ├── user_approval.py         # Approval system
-│   └── ...
+├── seo                          # Main CLI executable
+├── src/seo/                     # Integrated application package
+│   ├── __init__.py              # Package initialization
+│   ├── cli.py                   # Command-line interface
+│   ├── app.py                   # Main application class
+│   ├── config.py                # Configuration management
+│   ├── exporter.py              # Post export functionality
+│   ├── analyzer.py              # AI analysis functionality
+│   ├── recategorizer.py         # Recategorization functionality
+│   ├── seo_checker.py           # SEO quality checking
+│   ├── categories.py            # Category management
+│   └── approval.py              # User approval system
+├── scripts/                     # Legacy scripts (deprecated)
 ├── config.yaml                  # YAML configuration
 ├── .env                         # Environment variables
 ├── .env.example                 # Template
 ├── requirements.txt             # Dependencies
-├── output/reports/              # Generated CSV files
+├── output/                      # Generated files
 └── README.md
 ```
 
+## 📦 Installation
+
+For development/installation:
+
+```bash
+# Install in development mode
+pip install -e .
+
+# Or just use the executable directly
+./seo help
+```
+
 ## 🎯 Typical Workflow
 
 1. **Export posts** from all sites: