v0.16.2

feat(v0.16.2): richer queued cards + export conversation as markdown

Queued cards used to just say '<worker-name> (kind) · (예정)' which
gave no real info. Now they show:
  - the worker's role description (or first line of role prompt) as a
    placeholder for the upcoming task, italic + muted to distinguish
    from real spawned-task text
  - a row of badges: 대기 + model + effort + permissionMode when those
    diverge from defaults
This makes scanning the queue actually useful when several items are
declared in a single <plan>.

Also: ↓ export button in the chat header. Builds a markdown transcript
of the current session (role-labeled headers with timestamps, session
metadata block at the top) and triggers a Blob download named
<title>_<stamp>.md. Includes user / orchestrator / system lines.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>