fix(scrobble): 'Alles' (all-time) stats returned nothing — from=0 mapped to now

The client sends from=0 for the all-time range, but the string "0" is truthy, so it
was routed through _toEpochSec which maps 0 -> now, producing an empty window. Parse
'from' directly (0/absent/invalid -> all-time) instead. Affects web + Android.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

scrobble/scrobble-server.js

@@ -173,9 +173,11 @@ app.get('/scrobble/stats', async (req, res) => {
   if (!user) return res.status(401).json({ error: 'unauthorized' });
 
   const tz     = Math.trunc(Number(req.query.tz) || 0);
-  // Default window = all time. Route through _toEpochSec only when provided (it maps 0 → now).
+  // Default window = all time. Parse `from` directly — do NOT route through _toEpochSec, which maps
-  const from   = req.query.from ? _toEpochSec(req.query.from) : 0;
+  // 0 → now (so the client's explicit from=0 for "all time" would wrongly become an empty window).
-  const to     = req.query.to   ? _toEpochSec(req.query.to)   : Math.floor(Date.now() / 1000) + 1;
+  const fromN  = Number(req.query.from);
+  const from   = Number.isFinite(fromN) && fromN > 0 ? (fromN > 1e12 ? Math.floor(fromN / 1000) : Math.floor(fromN)) : 0;
+  const to     = req.query.to ? _toEpochSec(req.query.to) : Math.floor(Date.now() / 1000) + 1;
   const bucket = _STATS_FMT[req.query.bucket] ? req.query.bucket : 'day';
   const fmt    = _STATS_FMT[bucket];
   const limit  = Math.min(Math.max(parseInt(req.query.limit, 10) || 20, 1), 100);