Major refactor to flake, abstract non-trivial packages into their own

files (such as firefox/spotify-qt+librespot), create utils for reusable
function library

nix/home/common/theming.nix

@@ -0,0 +1,119 @@
+{
+  pkgs,
+  ...
+}:
+
+let
+  cursor_name = "Banana-Blue";
+  cursor_base_size = 32;
+
+  bananaCursorBlueTarball = pkgs.fetchurl {
+    url = "https://github.com/ful1e5/banana-cursor/releases/download/v2.0.0/Banana-Blue.tar.xz";
+    sha256 = "sha256-mpTrvgYiMfamMebtytY0bLouSbaP3qEqP8pgCFl+xPQ=";
+  };
+
+  banana_cursor_blue = pkgs.stdenv.mkDerivation {
+    pname = "banana-cursor-blue";
+    version = "2.0.0";
+    src = bananaCursorBlueTarball;
+    nativeBuildInputs = [ pkgs.xz ];
+
+    dontBuild = true;
+
+    installPhase = ''
+      runHook preInstall
+      # Define shell variable using Nix interpolation for $out and the outer Nix var cursorName
+      local themeInstallDir="$out/share/icons/${cursor_name}"
+      mkdir -p "$themeInstallDir"
+      # Use the outer Nix var cursorName and the builder's $version shell variable
+      echo "Unpacking and installing pre-built theme ${cursor_name} (v$version) to $themeInstallDir"
+
+      if tar -xJf $src --strip-components=1 -C "$themeInstallDir"; then
+        echo "Unpacked successfully with --strip-components=1."
+      else
+        echo "-----------------------------------------------------"
+        echo "WARNING: Unpacking with --strip-components=1 failed (archive might not have a single top-level dir)."
+        echo "Listing archive contents:"
+        tar -tf $src || echo "Failed to list archive contents."
+        echo "Attempting unpack without --strip-components=1..."
+        rm -rf "$themeInstallDir"; mkdir -p "$themeInstallDir" # Clean and recreate before retry
+        if tar -xJf $src -C "$themeInstallDir"; then
+           echo "Unpacked successfully without --strip-components=1."
+        else
+           echo "ERROR: Failed to unpack archive even without --strip-components=1."
+           exit 1
+        fi
+        echo "-----------------------------------------------------"
+      fi
+      runHook postInstall
+    '';
+
+    meta = with pkgs.lib; {
+      description = "Banana Cursor Theme (Pre-built Blue variant v2.0.0)";
+      homepage = "https://github.com/ful1e5/banana-cursor";
+      license = licenses.gpl3Only;
+      maintainers = with maintainers; [ eelco ];
+      platforms = platforms.linux;
+    };
+  };
+
+  cursor_package = banana_cursor_blue;
+
+  effective_cursor_size_str = toString cursor_base_size;
+in
+{
+  wayland.windowManager.sway = {
+    config = {
+      seat = {
+        "*" = {
+          # Sway uses this for its own cursor and for XWayland applications.
+          # It takes the theme name and base size. Sway should scale this based on output settings.
+          xcursor_theme = "${cursor_name} ${effective_cursor_size_str}";
+        };
+      };
+    };
+  };
+
+  # Home Manager Pointer Configuration
+  # This makes the theme available and sets X11/GTK defaults via Home Manager mechanisms.
+  home = {
+    pointerCursor = {
+      name = cursor_name;
+      size = cursor_base_size;
+      package = cursor_package;
+      x11.enable = true;
+      gtk.enable = true;
+      x11.defaultCursor = "left_ptr";
+    };
+    packages = with pkgs; [
+      (cursor_package)
+    ];
+  };
+
+  qt = {
+    enable = true;
+    platformTheme.name = "gtk";
+    style.name = "Nordic";
+  };
+
+  gtk = {
+    enable = true;
+    cursorTheme = {
+      name = cursor_name;
+      size = cursor_base_size; # GTK applications will use this base size.
+      package = cursor_package;
+    };
+    theme = {
+      package = pkgs.nordic;
+      name = "Nordic";
+    };
+  };
+
+  xresources.properties = {
+    "Xcursor.theme" = cursor_name;
+  };
+
+  home.sessionVariables = {
+    XCURSOR_THEME = cursor_name;
+  };
+}