feat(home): enable easyeffects for loudness normalization

Fix inconsistent volume across bilibili videos at the PipeWire level:
the easyeffects daemon auto-starts at login; an autogain + limiter
chain can be applied per-app (e.g. only to the browser).

Signed-off-by: Ryan Yin <xiaoyin_c@qq.com>

home/linux/gui/base/media.nix

@@ -29,5 +29,9 @@
 
   services = {
     playerctld.enable = true;
+    # PipeWire audio effects daemon, used for loudness normalization (e.g. bilibili
+    # videos with inconsistent volume). Configure plugins (autogain + limiter) once
+    # in the GUI; the daemon then auto-applies the preset at login.
+    easyeffects.enable = true;
   };
 }