dsh-session-namer: A Plugin for Naming New DSH Sessions

`dsh-session-namer` is a DeepSeek Harness (DSH) client plugin intended to address the issue that default auto-generated session titles may not meet expectations. By intercepting the creation of new sessions, it either prompts users to supply a name first or retains the original automatic naming logic, ensuring title control. The plugin supports real-time preview, theme adaptation, and truncation to the host's limit; it must be installed via a local `link:` method and depends on specific services.