feat: 重构图谱抽取 — 支持建筑规范文档的 8 种实体类型

- 实体类型改为：构件/设备/设施/指标/场所/材料/措施/条款
- 中文 prompt + 建筑规范领域 Few-shot 示例
- 前端图谱颜色、筛选项同步更新
- QA agent 系统提示词适配建筑规范领域

backend/pipeline/qa_agent.py

@@ -83,17 +83,14 @@ def make_tools(G: nx.Graph) -> list:
     def get_entities_by_type(entity_type: str) -> str:
         """List all entities of a specific type.
         Args:
-            entity_type: TECHNOLOGY, CONCEPT, PERSON, ORGANIZATION, or LOCATION.
+            entity_type: 构件, 设备, 设施, 指标, 场所, 材料, 措施, 条款, etc.
         """
-        t_upper = entity_type.strip().upper()
-        valid = {"TECHNOLOGY", "CONCEPT", "PERSON", "ORGANIZATION", "LOCATION"}
-        if t_upper not in valid:
-            present = sorted({d.get("type","") for _, d in G.nodes(data=True)})
-            return f"Unknown type '{entity_type}'. Present: {present}"
-        matches = [d for _, d in G.nodes(data=True) if d.get("type","") == t_upper]
+        t = entity_type.strip()
+        matches = [d for _, d in G.nodes(data=True) if d.get("type","") == t]
         if not matches:
-            return f"No {t_upper} entities found."
-        lines = [f"Found {len(matches)} {t_upper} entities:"]
+            present = sorted({d.get("type","") for _, d in G.nodes(data=True)})
+            return f"No '{entity_type}' entities found. Present types: {present}"
+        lines = [f"Found {len(matches)} {t} entities:"]
         for m in matches[:30]:
             lines.append(f"  \"{m['name']}\" (page={m.get('page',0)}, id={m['id']})")
         if len(matches) > 30:
@@ -148,15 +145,17 @@ def run_qa(
     )
 
     system_prompt = (
-        "You are a helpful assistant with access to a knowledge graph (KG) built from the user's documents.\n"
+        "You are a helpful assistant with access to a knowledge graph (KG) built from building code documents.\n"
+        "The KG contains entities extracted from building fire protection codes (建筑防火规范).\n"
+        "\n"
+        "Entity types include: 构件 (building components), 设备 (fire equipment), 设施 (facilities),\n"
+        "指标 (technical parameters), 场所 (building types/spaces), 材料 (materials),\n"
+        "措施 (fire measures), 条款 (regulation clauses).\n"
         "\n"
         "Guidelines:\n"
-        "- If the question is clearly unrelated to the KG (greetings, math, general knowledge, etc.), "
-        "answer directly WITHOUT using any tools.\n"
-        "- If the question might be answered by the KG (topics related to entities in the documents), "
-        "use the tools to search and explore before answering.\n"
-        "- When you DO use the KG, cite the entity names and types you found.\n"
-        "- If the KG has no relevant information, say so honestly and answer from general knowledge if possible.\n"
+        "- Use tools to search and explore the KG before answering.\n"
+        "- Cite the entity names and types you found.\n"
+        "- If the KG has no relevant information, say so honestly.\n"
         "\n"
         "Available tools: search entities by name, get neighbors, list entities by type, get graph overview."
     )