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/main.py

@@ -0,0 +1,58 @@
+"""
+GraphRAG Studio — FastAPI Backend
+Entry point: uvicorn main:app --host 0.0.0.0 --port 8000 --reload
+"""
+import sys
+from pathlib import Path
+
+# Ensure backend/ is in sys.path for absolute imports
+sys.path.insert(0, str(Path(__file__).parent))
+
+from dotenv import load_dotenv
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+load_dotenv(Path(__file__).parent / ".env", override=True)
+
+from routers import documents, indexing, kg, query, search, system
+
+app = FastAPI(
+    title="GraphRAG Studio API",
+    description="Multimodal RAG Q&A system backend — MinerU + LangExtract + Agentic-RAG",
+    version="1.0.0",
+    docs_url="/docs",
+    redoc_url="/redoc",
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# All routers under /api/v1. Each router carries its own sub-prefix.
+# documents.router  prefix="/documents" → /api/v1/documents
+# indexing.router   prefix="/index"     → /api/v1/index
+# kg.router         prefix="/kg"        → /api/v1/kg
+# query.router      prefix="/query"     → /api/v1/query
+# search.router     prefix="/search"    → /api/v1/search
+# system.router     no prefix           → /api/v1/health, /api/v1/system/...
+PREFIX = "/api/v1"
+app.include_router(documents.router, prefix=PREFIX)
+app.include_router(indexing.router,  prefix=PREFIX)
+app.include_router(kg.router,        prefix=PREFIX)
+app.include_router(query.router,     prefix=PREFIX)
+app.include_router(search.router,    prefix=PREFIX)
+app.include_router(system.router,    prefix=PREFIX)
+
+
+@app.get("/")
+async def root():
+    return {"msg": "GraphRAG Studio API v1.0.0", "docs": "/docs", "health": "/api/v1/health"}
+
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)