Remove swappy, obs-studio and meld

Update flake.lock to bump noctalia-shell and opencode inputs.
Tidy minor comments in desktop.nix and theming.nix.

modules/apps.nix

@@ -61,10 +61,7 @@
     # ═══════════════════════════════════════════════════════════════
     # SCREENSHOTS & RECORDING
     # ═══════════════════════════════════════════════════════════════
-    swappy # Screenshot annotation tool
-
     # Screen recording
-    obs-studio # Full-featured streaming/recording suite
     gpu-screen-recorder # Lightweight GPU-accelerated recorder (AMD/NVIDIA/Intel)
 
     # ═══════════════════════════════════════════════════════════════
@@ -80,7 +77,6 @@
     gnome-clocks # World clocks, alarms, timers
     baobab # Disk usage analyzer
     localsend # AirDrop-like file sharing (cross-platform)
-    meld # Visual diff and merge tool
 
     # ═══════════════════════════════════════════════════════════════
     # SYSTEM TOOLS

modules/desktop.nix

@@ -25,7 +25,7 @@
   # GUI privilege escalation
   security.polkit.enable = true;
 
-  # Polkit authentication agent (runs on login)
+  # Polkit authentication agent
   systemd.user.services.polkit-gnome-agent = {
     description = "Polkit GNOME Authentication Agent";
     wantedBy = [ "graphical-session.target" ];

modules/theming.nix

@@ -68,8 +68,6 @@
     # Icon theme
     papirus-icon-theme # Modern, flat icons
 
-    # Cursor theme (Adwaita cursor is included in adwaita-icon-theme above)
-
     # Qt theming
     libsForQt5.qt5ct # Qt5 configuration tool
     kdePackages.qt6ct # Qt6 configuration tool