Code Fold for AI Chats 제작자: kael

Adds a Fold / Unfold button to every code block in AI chat
interfaces, so long snippets stop pushing the conversation off the
screen. Code blocks are expanded by default — one click collapses
them.

• chat.qwen.ai (also qwen.ai, tongyi.aliyun.com)
• chat.deepseek.com

Adding a new site is a one-object change to src/sites.ts. See
Adding a site below.

• A pill-shaped ▾ Fold button appears in each code block's header,
  next to Copy / Download.
• Clicking it hides the code body and replaces it with a dimmed
  ▸ Click to unfold line.
• Clicking that line — or the button again — expands the block.
• On Qwen, expanding dispatches a resize event so the Monaco editor
  redraws its virtual viewport correctly.