feat: enhance configuration management and add error handling

src/middleware.ts

@@ -0,0 +1,36 @@
+import { NextFunction, Request, Response } from "express";
+import { AppError } from "./errors";
+import { createChildLogger } from "./logger";
+
+const logger = createChildLogger("middleware");
+
+export function errorHandler(
+  err: Error,
+  _req: Request,
+  res: Response,
+  _next: NextFunction,
+) {
+  if (err instanceof AppError) {
+    logger.error(
+      { code: err.code, statusCode: err.statusCode, message: err.message },
+      "Application error",
+    );
+    return res.status(err.statusCode).json({
+      error: err.code,
+      message: err.message,
+    });
+  }
+
+  logger.error({ error: err.message, stack: err.stack }, "Unexpected error");
+  res.status(500).json({
+    error: "INTERNAL_SERVER_ERROR",
+    message: "An unexpected error occurred",
+  });
+}
+
+export function notFoundHandler(_req: Request, res: Response) {
+  res.status(404).json({
+    error: "NOT_FOUND",
+    message: "Endpoint not found",
+  });
+}