Add Tdarr transcoding manager for bulk H.264→HEVC conversion

Runs Tdarr server with internal node on the mediaserver for managing
library-wide re-encoding to save disk space. Web UI at tdarr.nordhammer.it.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

services/nginx.nix

@@ -103,6 +103,7 @@ in
         # --- Other ---
         "games.nordhammer.it"  = proxy 8787;
         "search.nordhammer.it" = proxy 8087;
+        "tdarr.nordhammer.it"  = proxy 8265;
 
         # --- Protected by Authelia ---
         "camera.nordhammer.it"   = protectedProxy 1984;