feat: fix download-to-user matching, add cover art to downloads

- Fix seriesMap key (use Sonarr internal id, not tvdbId)
- Fix Sonarr tag resolution (use tag map like Radarr)
- Use sourceTitle for history record matching
- Fall back to embedded movie/series objects when API timeouts
- Add includeMovie/includeSeries params to queue/history API calls
- Add coverArt field to all download responses (TMDB poster URLs)
- Add cover art display to frontend download cards
- Fix user-summary route to use instance config and tag maps

server/utils/logger.js

@@ -0,0 +1,12 @@
+const fs = require('fs');
+const path = require('path');
+
+const logFile = fs.createWriteStream(path.join(__dirname, '../../server.log'), { flags: 'a' });
+
+function logToFile(message) {
+  logFile.write(`[${new Date().toISOString()}] ${message}\n`);
+}
+
+module.exports = {
+  logToFile
+};