GraphRAG Studio — initial commit: multimodal RAG system with KG visualization

Full-stack application for document-to-knowledge-graph pipeline:
- Backend: FastAPI + LangGraph ReAct agent + DeepSeek + MinerU parsing
- Frontend: React 19 + Vite + D3.js + shadcn/ui
- Pipeline: MinerU parsing → LangExtract entity extraction → KG building

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/routers/search.py

@@ -0,0 +1,43 @@
+"""E 组：搜索（3 个端点）"""
+from fastapi import APIRouter, Query, Request
+from fastapi.responses import JSONResponse
+
+from models.schemas import APIResponse
+from services import search_service as svc
+
+router = APIRouter(prefix="/search", tags=["Search"])
+
+
+@router.get("/entities")
+async def search_entities(q: str, type: str | None = None, limit: int = 15):
+    limit = min(limit, 100)
+    result = svc.search_entities(q, type, limit)
+    return APIResponse.ok(result)
+
+
+@router.get("/path")
+async def search_path(request: Request, max_hops: int = 3):
+    # 'from' is a Python keyword, read from raw query params
+    params = dict(request.query_params)
+    from_id = params.get("from")
+    to_id = params.get("to")
+
+    if not from_id or not to_id:
+        return JSONResponse(
+            status_code=400,
+            content=APIResponse.err(1001, "Parameters 'from' and 'to' are required").model_dump(),
+        )
+    max_hops = max(1, min(max_hops, 5))
+    result = svc.search_path(from_id, to_id, max_hops)
+    if result is None:
+        return JSONResponse(
+            status_code=404,
+            content=APIResponse.err(3001, "One or both nodes not found").model_dump(),
+        )
+    return APIResponse.ok(result)
+
+
+@router.get("/graph")
+async def search_graph(q: str, include_neighbors: bool = False):
+    result = svc.search_graph(q, include_neighbors)
+    return APIResponse.ok(result)