dsh-capture-window: Bypass Capture Window + /recall Engine

The `dsh-capture-window` plugin provides DSH with a side-channel capture window, allowing users to handle divergent ideas without interrupting the main task. It can be invoked via a hotkey or a floating widget and offers three context modes: blank, selection, and the default “last 10 messages,” ensuring that new sessions faithfully inherit the context. It also supports a draggable UI, multiple send shortcuts, and built-in model selection. Sticky notes within the capture window are in-memory, while new sessions inherit the directory and are persisted to storage. Built with a purely external add-on architecture and without modifying source code, it is well suited for long-context or transient ideas.