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>

backend/fix_dependencies.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+# 一键修复依赖问题脚本
+
+echo "🔧 开始修复依赖问题..."
+
+cd backend
+
+# 激活虚拟环境
+if [ -d "venv" ]; then
+    echo "✓ 找到虚拟环境"
+    source venv/bin/activate
+else
+    echo "✗ 未找到虚拟环境，正在创建..."
+    python3 -m venv venv
+    source venv/bin/activate
+fi
+
+echo "📦 卸载冲突的包..."
+pip uninstall -y numpy sentence-transformers huggingface-hub
+
+echo "📥 重新安装所有依赖..."
+pip install -r requirements.txt
+
+echo "✅ 验证安装..."
+python -c "import numpy; print(f'NumPy version: {numpy.__version__}')"
+python -c "import sentence_transformers; print(f'SentenceTransformers installed successfully')"
+python -c "import chromadb; print(f'ChromaDB installed successfully')"
+
+echo ""
+echo "✨ 修复完成！现在可以运行后端服务："
+echo "   python -m app.main"