refactor: extract http app setup

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/http/health.ts

@@ -0,0 +1,39 @@
+import { Router } from "express";
+import { getMetrics, uptimeGauge } from "../metrics";
+
+export interface HealthRoutesOptions {
+  adminPassword: string;
+  activeUserCount: () => number;
+  wsClientCount: () => number;
+}
+
+export function createHealthRoutes(options: HealthRoutesOptions) {
+  const router = Router();
+
+  router.get("/health", (_req, res) => {
+    res.json({
+      status: "ok",
+      timestamp: new Date().toISOString(),
+      uptime: process.uptime(),
+      activeUsers: options.activeUserCount(),
+      wsClients: options.wsClientCount(),
+    });
+  });
+
+  router.get("/metrics", async (_req, res) => {
+    res.set("Content-Type", "text/plain");
+    uptimeGauge.set(process.uptime());
+    res.send(await getMetrics());
+  });
+
+  router.post("/api/auth/login", (req, res) => {
+    const { password } = req.body;
+    if (password === options.adminPassword) {
+      res.json({ ok: true });
+      return;
+    }
+    res.status(401).json({ error: "Invalid password" });
+  });
+
+  return router;
+}