Audiobooks: built-in library, playback and synced progress through the audiobook player (classic frame kept)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

settings.js

@@ -47,4 +47,7 @@ async function handle(req, res) {
   } catch (e) { json(res, 500, { error: e.message }); }
 }
 
-module.exports = { handle, KEYS };
+// One saved value for the current person, read on the server (secret ones are decrypted).
+const get = k => { const v = load()[k]; return SECRET.has(k) && v && v._sealed ? unseal(v) : v; };
+
+module.exports = { handle, KEYS, get };