Phase 1: lock cron, reload chaud, argon2, providers, IMDb lookup, cache LRU, /health, /metrics, rate limit, UI dark, biome

routes/health.js

@@ -0,0 +1,35 @@
+// /health (JSON liveness/readiness) and /metrics (Prometheus exposition).
+
+import { getRatings } from '../lib/imdbRatings.js';
+import { imdbRatingsCount, registry } from '../lib/metrics.js';
+
+export default async function healthRoutes(fastify) {
+  fastify.get('/health', async (_req, reply) => {
+    reply.header('Cache-Control', 'no-store');
+    let ratings = 0;
+    let ratingsOk = false;
+    try {
+      const map = await getRatings();
+      ratings = map.size;
+      imdbRatingsCount.set(ratings);
+      ratingsOk = true;
+    } catch {
+      /* ignore — reported via ratingsOk */
+    }
+    const status = ratingsOk ? 'ok' : 'degraded';
+    reply.code(ratingsOk ? 200 : 503);
+    return {
+      status,
+      uptime: Math.round(process.uptime()),
+      pid: process.pid,
+      node: process.version,
+      memory_mb: Math.round(process.memoryUsage().rss / 1024 / 1024),
+      imdb_ratings: ratings,
+    };
+  });
+
+  fastify.get('/metrics', async (_req, reply) => {
+    reply.header('Content-Type', registry.contentType);
+    return registry.metrics();
+  });
+}