feat(app): add GET /health endpoint for HuggingFace Spaces liveness probe

server/app.py

@@ -33,3 +33,7 @@ app.add_middleware(
     allow_methods     = ["*"],
     allow_headers     = ["*"],
 )
+
+@app.get("/health")
+async def health_check():
+    return {"status": "healthy", "version": "0.1.0"}