Initial travel knowledge graph release

app/main.py

@@ -0,0 +1,59 @@
+"""City Knowledge Graph Admin — FastAPI entry point."""
+from __future__ import annotations
+
+from contextlib import asynccontextmanager
+
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.staticfiles import StaticFiles
+from starlette.exceptions import HTTPException as StarletteHTTPException
+
+from app.api import api_router
+from app.db import init_pool, close_pool
+
+
+class SPAStaticFiles(StaticFiles):
+    """Serve the admin SPA with client-side-routing fallback.
+
+    Any unknown path under /admin (e.g. /admin/login-v2, /admin/plaza/graph)
+    falls back to index.html so React Router can handle it on a hard
+    navigation or page refresh — instead of returning a 404.
+    """
+
+    async def get_response(self, path: str, scope):
+        try:
+            return await super().get_response(path, scope)
+        except StarletteHTTPException as exc:
+            if exc.status_code == 404:
+                return await super().get_response("index.html", scope)
+            raise
+
+
+@asynccontextmanager
+async def lifespan(_app: FastAPI):
+    await init_pool()
+    yield
+    await close_pool()
+
+
+app = FastAPI(
+    title="ZN-KG Admin",
+    version="0.1.0",
+    lifespan=lifespan,
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+app.include_router(api_router)
+
+# Serve built admin-web SPA (when available)
+try:
+    app.mount("/admin", SPAStaticFiles(directory="app/static/admin", html=True), name="admin-web")
+except Exception:
+    pass