fix: preserve panel install directory

panel-start.sh

@@ -52,8 +52,13 @@ tar -xzf "$ARCHIVE_PATH" -C "$TMP_DIR"
 EXTRACTED_DIR="$(find "$TMP_DIR" -mindepth 1 -maxdepth 1 -type d | head -n 1)"
 [ -n "$EXTRACTED_DIR" ] || fail "解压失败"
 
-rm -rf "$INSTALL_DIR"
-mv "$EXTRACTED_DIR" "$INSTALL_DIR"
+if [ ! -d "$INSTALL_DIR" ]; then
+  mv "$EXTRACTED_DIR" "$INSTALL_DIR"
+else
+  log "保留现有安装目录，仅覆盖仓库文件"
+  cp -r "$EXTRACTED_DIR"/. "$INSTALL_DIR"/
+  rm -rf "$EXTRACTED_DIR"
+fi
 rm -rf "$TMP_DIR" "$ARCHIVE_PATH"
 
 cd "$INSTALL_DIR"