Hero endpoint: parallel upstream calls, Server-Timing, and warm caches after boot

ddiff --git a/server/home/routes.js b/server/home/routes.js
iindex 2d49bbd2..ab3fdad9 100644
---- a/server/home/routes.js
++++ b/server/home/routes.js
@@@ -178,9 +178,18 @@ router.get('/stats/series/:metric', (req, res) => {
      res.json(series);
  });
  
--async function heroStats() {
++async function heroStats(timing) {
++    const mark = (k, a) => { if (timing) timing[k] = Date.now() - a; };
++    let a = Date.now();
      const stats = { ...db.getHomeStats() };
--    const m = await _mediaStatsCached();
++    mark('db', a);
++    // Media stats and the network coin ledger are independent upstream calls; they used to be awaited
++    // one after the other, so a cold cache paid for both in sequence.
++    a = Date.now();
++    const [m, c] = await Promise.all([
++        _mediaStatsCached().then(v => { mark('media_stats', a); return v; }),
++        require('../monetization/wallet-client').networkCoinStats().then(v => { mark('coins', a); return v; }).catch(() => null),
++    ]);
      if (m) {
          stats.vods = m.vods;
          stats.clips = m.clips;
@@@ -194,7 +203,6 @@ async function heroStats() {
      // currency people earn everywhere, the other is per-channel. The ledger lives on
      // OpenVibe.Network, so this is a cached internal call that is allowed to come back empty.
      try {
--        const c = await require('../monetization/wallet-client').networkCoinStats();
          if (c) {
              stats.coinsEarned = c.earned;
              stats.coinsSpent = c.spent;
@@@ -249,13 +257,29 @@ router.get('/stats-live', (req, res) => {
      }
  });
  
++async function buildHero(timing) {
++    const t0 = Date.now();
++    // The stats and the media pool do not depend on each other either.
++    const [stats, mediaItems] = await Promise.all([
++        heroStats(timing),
++        (async () => { const a = Date.now(); const v = await heroMedia(); if (timing) timing.media_pool = Date.now() - a; return v; })(),
++    ]);
++    let a = Date.now();
++    // 24h viewer trend for the hero sparkline (sampled every 5 min by the sampler).
++    try { stats.viewerTrend = db.getViewerTrend(24, 48); } catch { stats.viewerTrend = []; }
++    const payload = { stats, media: mediaItems, moments: heroMoments(), slogans: heroSlogans() };
++    if (timing) { timing.local = Date.now() - a; timing.total = Date.now() - t0; }
++    return payload;
++}
++
  router.get('/hero', async (req, res) => {
      try {
          res.set('Cache-Control', 'public, max-age=20');
--        const stats = await heroStats();
--        // 24h viewer trend for the hero sparkline (sampled every 5 min by the sampler).
--        try { stats.viewerTrend = db.getViewerTrend(24, 48); } catch { stats.viewerTrend = []; }
--        res.json({ stats, media: await heroMedia(), moments: heroMoments(), slogans: heroSlogans() });
++        const timing = {};
++        const payload = await buildHero(timing);
++        // Where the time went, visible in devtools and to curl -I. Durations only, no data.
++        res.set('Server-Timing', Object.entries(timing).map(([k, v]) => `${k};dur=${v}`).join(', '));
++        res.json(payload);
      } catch (err) {
          console.error('[Home] hero error:', err.message);
          res.status(500).json({ error: 'Failed to load hero' });
@@@ -507,3 +531,8 @@ module.exports = router;
  module.exports.startViewerSampler = startViewerSampler;
  module.exports.FALLBACK_AUDIENCES = FALLBACK_AUDIENCES;
  module.exports.FALLBACK_QUIPS = FALLBACK_QUIPS;
++
++// Warm the hero caches once boot has finished (~6s on production). Every deploy restarts the process with empty caches, and
++// the first home page load after it used to wait on every upstream call cold (~2.3s measured right
++// after a deploy). The timer is unref'd so it never holds the process open.
++setTimeout(() => { buildHero(null).catch(() => {}); }, 15000).unref?.();