dsh-wide-conversation: Customize the Conversation Column Width in the DSH Client

dsh-wide-conversation is a DSH plugin designed to address the restricted reading width of the conversation column on wide screens. It allows users to set the conversation width as a percentage of the available width (default: 100%). By overriding the built-in 680–920px constraint via CSS, it takes effect in the Web client without a build step and supports adjusting the `widthPercent` parameter through the configuration card.