Full rewrite

.github/scripts/convert-to-png.sh

@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+# Every gif in wallpapers/ must have a same-named static .png counterpart
+# (see README.md). This hook generates the missing ones from the gif's
+# first frame and stages them, so a commit adding a gif automatically
+# gets its png alongside it.
+
+set -uo pipefail
+
+wallpapers_dir="wallpapers"
+changed=0
+
+if [[ ! -d "$wallpapers_dir" ]]; then
+  exit 0
+fi
+
+if ! command -v magick >/dev/null 2>&1; then
+  echo "❌ imagemagick (magick) is required but was not found in PATH"
+  exit 1
+fi
+
+shopt -s nullglob
+for gif in "$wallpapers_dir"/*.gif; do
+  basename="${gif%.gif}"
+  png="$basename.png"
+
+  if [[ -f "$png" ]]; then
+    continue
+  fi
+
+  echo "Generating $png from $(basename "$gif")"
+  if ! magick "${gif}[0]" "$png"; then
+    echo "❌ Failed to generate $png"
+    exit 1
+  fi
+  git add "$png"
+  changed=1
+done
+
+if [[ "$changed" -eq 1 ]]; then
+  echo "New static png(s) were generated and staged, please commit again."
+  exit 1
+fi
+
+exit 0