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

lib/imdbMapping.js

@@ -0,0 +1,35 @@
+// Loads imdb2movie.json / imdb2tv.json into memory and reloads on mtime change.
+
+import { readFile, stat } from 'node:fs/promises';
+import { join } from 'node:path';
+import { TMDBINTEGRAL_DIR } from '../config.js';
+
+const cache = { movie: null, tv: null };
+const mtimes = { movie: 0, tv: 0 };
+
+async function loadOne(type) {
+  const file = join(TMDBINTEGRAL_DIR, `imdb2${type}.json`);
+  const st = await stat(file);
+  if (cache[type] && st.mtimeMs === mtimes[type]) return cache[type];
+  const obj = JSON.parse(await readFile(file, 'utf8'));
+  cache[type] = new Map(Object.entries(obj).map(([k, v]) => [k, Number(v)]));
+  mtimes[type] = st.mtimeMs;
+  return cache[type];
+}
+
+export async function lookupImdb(imdbId) {
+  // Try movie first, then tv (matches PHP behaviour of exhaustive lookup).
+  try {
+    const movieMap = await loadOne('movie');
+    if (movieMap.has(imdbId)) return { type: 'movie', tmdb: movieMap.get(imdbId) };
+  } catch {
+    /* file may be missing on a fresh install */
+  }
+  try {
+    const tvMap = await loadOne('tv');
+    if (tvMap.has(imdbId)) return { type: 'tv', tmdb: tvMap.get(imdbId) };
+  } catch {
+    /* same */
+  }
+  return null;
+}