dsh-quick-attach: Convert pasted images to paths that can be sent to AI

ximisi/dsh-quick-attach is an MIT-licensed plugin for the DSH web GUI designed to simplify image recognition workflows. It eliminates the tedious steps of manually saving images and typing paths, allowing users to paste images directly into the session input box. The plugin automatically saves images to the configured directory and appends the absolute path to the message draft, sending it along with the message to the AI for processing via its file tools and visual capabilities. The plugin handles saving and configuration through the host interface and intercepts input box paste events on the client side. After installation, users need to enable and configure the save directory in the settings (defaulting to `<DSH_HOME>/quick-attach`). Typical usage involves pasting an image, which is automatically saved and the path sent. Please note that this feature applies only to the session input box and replaces the native image attachment functionality.