Phase 5: 知识推理与问答增强

- 新增 knowledge_reasoner.py 推理引擎
- 支持因果/对比/时序/关联四种推理类型
- 智能项目总结 API (全面/高管/技术/风险)
- 实体关联路径发现功能
- 前端推理面板 UI 和交互
- 更新 API 端点和健康检查

Refs: Phase 5 开发任务

backend/main.py

@@ -61,6 +61,12 @@ try:
 except ImportError:
     LLM_CLIENT_AVAILABLE = False
 
+try:
+    from knowledge_reasoner import get_knowledge_reasoner, KnowledgeReasoner, ReasoningType
+    REASONER_AVAILABLE = True
+except ImportError:
+    REASONER_AVAILABLE = False
+
 app = FastAPI(title="InsightFlow", version="0.3.0")
 
 app.add_middleware(
@@ -983,14 +989,15 @@ async def get_entity_mentions(entity_id: str):
 async def health_check():
     return {
         "status": "ok",
-        "version": "0.5.0",
-        "phase": "Phase 5 - Timeline View",
+        "version": "0.6.0",
+        "phase": "Phase 5 - Knowledge Reasoning",
         "oss_available": OSS_AVAILABLE,
         "tingwu_available": TINGWU_AVAILABLE,
         "db_available": DB_AVAILABLE,
         "doc_processor_available": DOC_PROCESSOR_AVAILABLE,
         "aligner_available": ALIGNER_AVAILABLE,
-        "llm_client_available": LLM_CLIENT_AVAILABLE
+        "llm_client_available": LLM_CLIENT_AVAILABLE,
+        "reasoner_available": REASONER_AVAILABLE
     }
 
 
@@ -1336,6 +1343,164 @@ async def get_entity_timeline(entity_id: str):
     }
 
 
+# ==================== Phase 5: 知识推理与问答增强 API ====================
+
+class ReasoningQuery(BaseModel):
+    query: str
+    reasoning_depth: str = "medium"  # shallow/medium/deep
+    stream: bool = False
+
+
+@app.post("/api/v1/projects/{project_id}/reasoning/query")
+async def reasoning_query(project_id: str, query: ReasoningQuery):
+    """
+    增强问答 - 基于知识推理的智能问答
+    
+    支持多种推理类型：
+    - 因果推理：分析原因和影响
+    - 对比推理：比较实体间的异同
+    - 时序推理：分析时间线和演变
+    - 关联推理：发现隐含关联
+    """
+    if not DB_AVAILABLE or not REASONER_AVAILABLE:
+        raise HTTPException(status_code=500, detail="Knowledge reasoner not available")
+    
+    db = get_db_manager()
+    reasoner = get_knowledge_reasoner()
+    
+    project = db.get_project(project_id)
+    if not project:
+        raise HTTPException(status_code=404, detail="Project not found")
+    
+    # 获取项目上下文
+    project_context = db.get_project_summary(project_id)
+    
+    # 获取知识图谱数据
+    entities = db.list_project_entities(project_id)
+    relations = db.list_project_relations(project_id)
+    
+    graph_data = {
+        "entities": [{"id": e.id, "name": e.name, "type": e.type, "definition": e.definition} for e in entities],
+        "relations": relations
+    }
+    
+    # 执行增强问答
+    result = await reasoner.enhanced_qa(
+        query=query.query,
+        project_context=project_context,
+        graph_data=graph_data,
+        reasoning_depth=query.reasoning_depth
+    )
+    
+    return {
+        "answer": result.answer,
+        "reasoning_type": result.reasoning_type.value,
+        "confidence": result.confidence,
+        "evidence": result.evidence,
+        "knowledge_gaps": result.gaps,
+        "project_id": project_id
+    }
+
+
+@app.post("/api/v1/projects/{project_id}/reasoning/inference-path")
+async def find_inference_path(
+    project_id: str,
+    start_entity: str,
+    end_entity: str
+):
+    """
+    发现两个实体之间的推理路径
+    
+    在知识图谱中搜索从 start_entity 到 end_entity 的路径
+    """
+    if not DB_AVAILABLE or not REASONER_AVAILABLE:
+        raise HTTPException(status_code=500, detail="Knowledge reasoner not available")
+    
+    db = get_db_manager()
+    reasoner = get_knowledge_reasoner()
+    
+    project = db.get_project(project_id)
+    if not project:
+        raise HTTPException(status_code=404, detail="Project not found")
+    
+    # 获取知识图谱数据
+    entities = db.list_project_entities(project_id)
+    relations = db.list_project_relations(project_id)
+    
+    graph_data = {
+        "entities": [{"id": e.id, "name": e.name, "type": e.type} for e in entities],
+        "relations": relations
+    }
+    
+    # 查找推理路径
+    paths = reasoner.find_inference_paths(start_entity, end_entity, graph_data)
+    
+    return {
+        "start_entity": start_entity,
+        "end_entity": end_entity,
+        "paths": [
+            {
+                "path": path.path,
+                "strength": path.strength,
+                "path_description": " -> ".join([p["entity"] for p in path.path])
+            }
+            for path in paths[:5]  # 最多返回5条路径
+        ],
+        "total_paths": len(paths)
+    }
+
+
+class SummaryRequest(BaseModel):
+    summary_type: str = "comprehensive"  # comprehensive/executive/technical/risk
+
+
+@app.post("/api/v1/projects/{project_id}/reasoning/summary")
+async def project_summary(project_id: str, req: SummaryRequest):
+    """
+    项目智能总结
+    
+    根据类型生成不同侧重点的总结：
+    - comprehensive: 全面总结
+    - executive: 高管摘要
+    - technical: 技术总结
+    - risk: 风险分析
+    """
+    if not DB_AVAILABLE or not REASONER_AVAILABLE:
+        raise HTTPException(status_code=500, detail="Knowledge reasoner not available")
+    
+    db = get_db_manager()
+    reasoner = get_knowledge_reasoner()
+    
+    project = db.get_project(project_id)
+    if not project:
+        raise HTTPException(status_code=404, detail="Project not found")
+    
+    # 获取项目上下文
+    project_context = db.get_project_summary(project_id)
+    
+    # 获取知识图谱数据
+    entities = db.list_project_entities(project_id)
+    relations = db.list_project_relations(project_id)
+    
+    graph_data = {
+        "entities": [{"id": e.id, "name": e.name, "type": e.type} for e in entities],
+        "relations": relations
+    }
+    
+    # 生成总结
+    summary = await reasoner.summarize_project(
+        project_context=project_context,
+        graph_data=graph_data,
+        summary_type=req.summary_type
+    )
+    
+    return {
+        "project_id": project_id,
+        "summary_type": req.summary_type,
+        **summary
+    }
+
+
 # Serve frontend - MUST be last to not override API routes
 app.mount("/", StaticFiles(directory="frontend", html=True), name="frontend")