fix: move health endpoint before auth middleware, add curl to alpine

Dockerfile

@@ -1,4 +1,5 @@
 FROM node:20-alpine
+RUN apk add --no-cache curl
 WORKDIR /app
 COPY package.json ./
 RUN npm install --production

server.js

@@ -65,6 +65,10 @@ const smtp = new SMTPServer({
 
 const app = express();
 
+app.get("/health", (_req, res) => {
+  res.json({ status: "ok", stored: store.size });
+});
+
 app.use((req, res, next) => {
   if (API_KEY && req.headers["x-api-key"] !== API_KEY) {
     return res.status(401).json({ error: "unauthorized" });
@@ -72,10 +76,6 @@ app.use((req, res, next) => {
   next();
 });
 
-app.get("/health", (_req, res) => {
-  res.json({ status: "ok", stored: store.size });
-});
-
 app.get("/mail/:address", (req, res) => {
   const addr = req.params.address.toLowerCase();
   const mails = store.get(addr) || [];