feat: implement ERP AI Assistant Phase 1

Backend (FastAPI + SQLAlchemy + Claude API + RAG):
- Config management with Pydantic v2
- Database engine with connection pooling and SQL injection prevention
- AI engine with Claude API integration (support custom base URL)
- RAG engine with ChromaDB and sentence-transformers
- Requirement analysis service
- Config generation service
- Executor engine with SQL validation
- REST API endpoints: /analyze, /generate, /execute

Frontend (Vue 3 + Element Plus + Pinia):
- Complete 3-step workflow: analyze → generate → execute
- Step indicator with progress visualization
- Analysis result display with field table
- SQL preview with monospace font
- Execute confirmation dialog with safety warning
- Execution result display
- State management with Pinia
- API service integration

Security:
- SQL injection prevention with parameterized queries
- Dangerous SQL operation blocking
- Database password URL encoding
- Transaction auto-rollback
- Pydantic config validation

Features:
- Natural language requirement analysis
- Automated SQL configuration generation
- Safe execution with human review
- LAN access support
- Custom Claude API endpoint support

Documentation:
- README with quick start guide
- Quick start guide
- LAN access configuration
- Dependency fixes guide
- Claude API configuration
- Git operation guide
- Implementation report

Dependencies fixed:
- numpy<2.0.0 for chromadb compatibility
- sentence-transformers==2.7.0 for huggingface_hub compatibility

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,104 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# Virtual Environment
+venv/
+env/
+ENV/
+.venv
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# Environment Variables
+.env
+.env.local
+.env.*.local
+
+# Logs
+*.log
+logs/
+
+# Database
+*.db
+*.sqlite
+*.sqlite3
+
+# Testing
+.pytest_cache/
+.coverage
+htmlcov/
+.tox/
+
+# ChromaDB
+backend/knowledge_base/chroma_db/
+
+# Node.js
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+
+# Build
+frontend/dist/
+frontend/dist-ssr/
+frontend/*.local
+
+# Editor directories and files
+frontend/.vscode/
+frontend/.idea/
+frontend/*.suo
+frontend*.ntvs*
+frontend*.njsproj
+frontend*.sln
+frontend*.sw?
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Project specific
+erp-doc/
+backend/knowledge_base/documents/*.docx
+backend/knowledge_base/documents/*.xlsx
+backend/knowledge_base/documents/*.pdf
+backend/knowledge_base/documents/*.pptx
+backend/knowledge_base/documents/*.vsdx
+backend/knowledge_base/documents/*.xls
+
+# Temporary files
+*.tmp
+*.temp
+*.bak
+*.swp
+*~
+
+# Archives
+*.zip
+*.tar.gz
+*.rar
+*.7z