docs: 添加中文文档，新增前端和后端代码

- 新增 README_CN.md 中文文档
- 新增 frontend/ Vue 3 前端项目
- 新增 web/ FastAPI 后端项目

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

web/backend/main.py

@@ -0,0 +1,33 @@
+"""FastAPI application entry point for BtToxin Pipeline Web Backend.
+
+Requirements: 7.5
+"""
+
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from .config import settings
+
+# Create FastAPI application
+app = FastAPI(
+    title="BtToxin Pipeline Web API",
+    description="Web API for BtToxin Pipeline - analyze genome files for insecticidal proteins",
+    version="0.1.0",
+    docs_url="/api/docs" if settings.debug else None,
+    redoc_url="/api/redoc" if settings.debug else None,
+)
+
+# Configure CORS
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=settings.cors_origins,
+    allow_credentials=True,
+    allow_methods=["GET", "POST"],
+    allow_headers=["*"],
+)
+
+
+@app.get("/api/health")
+async def health_check():
+    """Health check endpoint."""
+    return {"status": "healthy"}