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/tests/test_prompts.py

@@ -0,0 +1,36 @@
+"""Tests for prompt templates."""
+
+from app.core.prompts import SYSTEM_PROMPT, ANALYZE_PROMPT_TEMPLATE, GENERATE_PROMPT_TEMPLATE
+
+
+def test_system_prompt_exists():
+    """测试系统 Prompt 存在"""
+    assert SYSTEM_PROMPT is not None
+    assert len(SYSTEM_PROMPT) > 100
+    # Test for stable characteristics rather than exact wording
+    assert "ERP" in SYSTEM_PROMPT
+    assert "配置" in SYSTEM_PROMPT
+
+
+def test_analyze_prompt_template():
+    """测试需求解析模板"""
+    rendered = ANALYZE_PROMPT_TEMPLATE.format(
+        user_input="创建销售订单",
+        knowledge_context="测试知识",
+        existing_tables="测试表"
+    )
+    assert "创建销售订单" in rendered
+    assert "测试知识" in rendered
+    assert "测试表" in rendered
+
+
+def test_generate_prompt_template():
+    """测试配置生成模板"""
+    rendered = GENERATE_PROMPT_TEMPLATE.format(
+        requirements="需求分析结果",
+        platform_rules="平台规则",
+        similar_cases="类似案例"
+    )
+    assert "需求分析结果" in rendered
+    assert "平台规则" in rendered
+    assert "类似案例" in rendered