fix: make API not-found responses deterministic

server/app.ts

@@ -1640,13 +1640,24 @@ export async function buildApp(database: DatabaseContext, config: AppConfig) {
     return reply.send(await safeReadStream(config.exportsDir, job.filePath));
   });
 
-  if (existsSync(config.webDir)) {
+  const hasWeb = existsSync(config.webDir);
+  if (hasWeb) {
     await app.register(fastifyStatic, { root: config.webDir, wildcard: false });
-    app.setNotFoundHandler((request, reply) => {
-      if (request.url.startsWith("/api/")) return reply.code(404).send(errorPayload(request, new AppError(404, "NOT_FOUND", "接口不存在")));
-      return reply.sendFile("index.html");
+  }
+  // Keep API errors structured even when the production frontend has not been
+  // built yet (for example in a clean CI checkout or an API-only process).
+  app.setNotFoundHandler((request, reply) => {
+    if (request.url.split("?", 1)[0]!.startsWith("/api/")) {
+      return reply.code(404).send(errorPayload(request, new AppError(404, "NOT_FOUND", "接口不存在")));
+    }
+    if (hasWeb) return reply.sendFile("index.html");
+    return reply.code(404).send({
+      message: `Route ${request.method}:${request.url} not found`,
+      error: "Not Found",
+      statusCode: 404,
     });
-  } else {
+  });
+  if (!hasWeb) {
     app.get("/", async () => ({ name: "TallyNote", mode: "api", hint: "开发界面运行在 Vite 端口" }));
   }