hyprland: remove dead config (WLR_DRM_DEVICES, pamixer, stale CSS, old activation)

- WLR_DRM_DEVICES: wlroots env var ignored by Aquamarine, AQ_DRM_DEVICES already set
- pamixer: not referenced anywhere, volume handled by swayosd-client
- #network.disconnected CSS: no network module in waybar config
- #custom-tray-toggle CSS: renamed to #custom-tray-handle to match actual module
- removeOldHyprlandConf activation: one-time migration already completed

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

settings/hyprland.nix

@@ -51,7 +51,6 @@ in
       wl-clipboard
       cliphist
       brightnessctl
-      pamixer
       swayosd
       playerctl
       hyprpaper
@@ -229,7 +228,6 @@ in
             ${lib.optionalString isGaming ''
             -- GPU pinning — Navi 22 is card1 on the dual-GPU gaming box.
             hl.env("AQ_DRM_DEVICES", "/dev/dri/card1")
-            hl.env("WLR_DRM_DEVICES", "/dev/dri/card1")
             hl.env("DRI_PRIME", "pci-0000_03_00_0")
             ''}
 
@@ -554,8 +552,7 @@ in
             color: @base05;
           }
 
-          #pulseaudio.muted,
-          #network.disconnected {
+          #pulseaudio.muted {
             color: @base03;
           }
 
@@ -563,7 +560,7 @@ in
             margin-right: 6px;
           }
 
-          #custom-tray-toggle {
+          #custom-tray-handle {
             padding: 0 0px;
             color: @base05;
           }
@@ -577,13 +574,6 @@ in
         '';
       };
 
-      # The old hyprlang hyprland.conf (with `# autogenerated = 1`) is not
-      # managed by HM after switching to configType = "lua", so Hyprland still
-      # finds it and shows the "autogenerated config" banner. Remove it once on
-      # every activation so it can never linger.
-      home.activation.removeOldHyprlandConf = lib.hm.dag.entryAfter [ "writeBoundary" ] ''
-        rm -f "${config.xdg.configHome}/hypr/hyprland.conf"
-      '';
     };
   };
 }