feat(clone-app): add download-apk.sh with retries and xapk/apk detection

plugins/clone-app/skills/clone-app/scripts/download-apk.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+package="${1:-}"
+out_dir="${2:-}"
+curl_bin="${CLONE_APP_CURL:-curl}"
+
+if [[ -z "$package" || -z "$out_dir" ]]; then
+  echo "ERROR: usage: download-apk.sh <package> <out-dir>" >&2
+  exit 1
+fi
+
+mkdir -p "$out_dir"
+tmp_file="$out_dir/app.download"
+url="https://d.apkpure.com/b/APK/${package}?version=latest"
+
+ok=0
+for attempt in 1 2 3; do
+  if "$curl_bin" -L --fail "$url" --output "$tmp_file" 2>/dev/null; then
+    ok=1; break
+  fi
+  echo "download attempt $attempt failed, retrying..." >&2
+  sleep 1
+done
+
+if [[ "$ok" -ne 1 ]]; then
+  echo "ERROR: failed to download $package after 3 attempts from $url" >&2
+  rm -f "$tmp_file"
+  exit 1
+fi
+
+# Decide extension: both APK and XAPK are ZIPs. XAPK = zip containing manifest.json + >=2 .apk entries.
+ext="apk"
+if entries="$(unzip -Z1 "$tmp_file" 2>/dev/null)"; then
+  apk_count="$(grep -c '\.apk$' <<<"$entries" || true)"
+  if grep -q '^manifest\.json$' <<<"$entries" && [[ "$apk_count" -ge 1 ]]; then
+    ext="xapk"
+  fi
+fi
+
+final="$out_dir/app.$ext"
+mv "$tmp_file" "$final"
+echo "$final"

plugins/clone-app/tests/test-download-apk.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+set -uo pipefail
+SCRIPT="$(dirname "$0")/../skills/clone-app/scripts/download-apk.sh"
+fail=0
+check() { [[ "$2" == "$3" ]] && echo "PASS: $1" || { echo "FAIL: $1 — expected '$2' got '$3'"; fail=1; }; }
+
+tmp="$(mktemp -d)"
+
+# Stub curl: writes a minimal zip containing manifest.json + two apk entries → xapk
+cat > "$tmp/fakecurl-xapk.sh" <<'EOF'
+#!/usr/bin/env bash
+out=""; prev=""
+for a in "$@"; do [[ "$prev" == "--output" ]] && out="$a"; prev="$a"; done
+workdir="$(mktemp -d)"
+echo '{}' > "$workdir/manifest.json"
+echo 'a' > "$workdir/base.apk"; echo 'b' > "$workdir/config.apk"
+( cd "$workdir" && zip -q -r "$out" . )
+exit 0
+EOF
+chmod +x "$tmp/fakecurl-xapk.sh"
+
+path="$(CLONE_APP_CURL="$tmp/fakecurl-xapk.sh" bash "$SCRIPT" com.example.app "$tmp/out" 2>/dev/null)"; rc=$?
+check "xapk exit 0" "0" "$rc"
+check "xapk extension" "xapk" "${path##*.}"
+
+# Stub curl that always fails → exit 1 after retries
+cat > "$tmp/fakecurl-fail.sh" <<'EOF'
+#!/usr/bin/env bash
+exit 22
+EOF
+chmod +x "$tmp/fakecurl-fail.sh"
+out2="$(CLONE_APP_CURL="$tmp/fakecurl-fail.sh" bash "$SCRIPT" com.example.app "$tmp/out2" 2>/dev/null)"; rc2=$?
+check "fail exit 1" "1" "$rc2"
+
+rm -rf "$tmp"
+exit $fail