feat(glyph): tune transmission settings for RPC performance (#325)

With 2000+ torrents loaded, Transmission's RPC takes 9-17 seconds to
respond. Increase disk write cache from default 4MB to 256MB and enable
download queue to reduce I/O contention blocking the RPC thread.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: stackptr

hosts/glyph/services/torrents.nix

@@ -50,6 +50,11 @@
           --form-string "url_title=View torrents" \
           https://api.pushover.net/1/messages.json
       '';
+      cache-size-mb = 256;
+      download-queue-enabled = true;
+      download-queue-size = 5;
+      queue-stalled-enabled = true;
+      queue-stalled-minutes = 30;
       utp-enabled = false;
       watch-dir = "/mnt/torrents/watch";
       watch-dir-enabled = true;