feat: add signtool to plugin repository

- Migrate signing tool from GoTunnel main project
- Self-contained, no external dependencies
- Updated CI workflow to build locally

scripts/sign-all.sh

@@ -15,13 +15,19 @@ fi
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 REPO_ROOT="$(dirname "$SCRIPT_DIR")"
+SIGNTOOL="$REPO_ROOT/signtool"
+
+# 如果 signtool 不存在，尝试构建
+if [ ! -f "$SIGNTOOL" ]; then
+    echo "Building signtool..."
+    cd "$REPO_ROOT"
+    go build -o signtool ./tools/signtool
+fi
 
 cd "$REPO_ROOT"
 
 for manifest in plugins/*/manifest.json; do
-    if [ ! -f "$manifest" ]; then
-        continue
-    fi
+    [ -f "$manifest" ] || continue
 
     dir=$(dirname "$manifest")
     name=$(jq -r '.name' "$manifest")
@@ -34,7 +40,7 @@ for manifest in plugins/*/manifest.json; do
     fi
 
     echo "Signing: $name v$version"
-    signtool sign -key "$KEY_FILE" \
+    "$SIGNTOOL" sign -key "$KEY_FILE" \
         -name "$name" \
         -version "$version" \
         "$plugin_file"