long-draft-input: Displaying Attachment-Style Summary Cards on DSH Long Drafts

long-draft-input is a standalone MIT-licensed plugin for DeepSeek Harness (DSH) 0.1.0-rc.5, designed to optimize the long-draft input experience. When the draft in the input box exceeds a threshold (default 2,000 characters), the plugin collapses the draft into an attachment-style summary card showing a first-line preview, character count, and line count, while expanding the send box upward; when below the threshold, the original behavior is preserved. The full text remains intact in `input.draft`, and submission still goes through the original `inputActions.submit()`, without altering draft state, message format, or the submission path. Users can add supplementary text in the collapsed state, click to restore the original text box for editing, or remove the long text and keep only the supplementary content. The plugin integrates via `conversation.input.d