Add Claude Desktop extensions (.mcpb) for WordCraft and GridCraft.

Ship unsigned MCPB packages built from the ArtCraft Launcher CLIs, with install docs and skill 0.2.0 updates.

scripts/package-mcpb.sh

@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+# Builds dist/<name>-v<version>.mcpb from skills/<name>/extension/
+# Steps: fetch-cli, mcpb validate, mcpb pack. Unsigned (no cert).
+# Usage: scripts/package-mcpb.sh <skill-name> [cli-path]
+set -euo pipefail
+source "$(dirname "$0")/lib.sh"
+
+name="${1:-}"
+cli_path="${2:-}"
+if [[ -z "$name" ]]; then
+  echo "Aufruf: scripts/package-mcpb.sh <skill-name> [cli-path]" >&2
+  exit 1
+fi
+
+dir="$SKILLS_DIR/$name"
+ext="$dir/extension"
+[[ -f "$ext/manifest.json" ]] || { echo "skills/$name/extension/ fehlt." >&2; exit 1; }
+
+ver="$(skill_version "$dir")"
+[[ -n "$ver" ]] || { echo "CHANGELOG von $name hat keine Version." >&2; exit 1; }
+
+if [[ -n "$cli_path" ]]; then
+  bash "$(dirname "$0")/fetch-cli.sh" "$name" "$cli_path"
+else
+  bash "$(dirname "$0")/fetch-cli.sh" "$name"
+fi
+
+man_ver="$(python3 -c 'import json,sys; print(json.load(open(sys.argv[1],encoding="utf-8"))["version"])' "$ext/manifest.json")"
+if [[ "$man_ver" != "$ver" ]]; then
+  echo "manifest.json version '$man_ver' != CHANGELOG '$ver'." >&2
+  exit 1
+fi
+
+mkdir -p "$DIST_DIR"
+out="$DIST_DIR/$name-v$ver.mcpb"
+rm -f "$out"
+
+(
+  cd "$ext"
+  npx --yes @anthropic-ai/mcpb validate .
+  npx --yes @anthropic-ai/mcpb pack . "$out"
+)
+
+echo
+echo "dist/$name-v$ver.mcpb"
+unzip -l "$out"