0.6.1 — bare approve refuses unseen plans; Approval card switch

• Bare /planmode approve refuses changed submissions (#48) even after a denial or stale answer, and refuses a newer file
  that was never submitted or a submitted file that was deleted; review with /planmode show, then resubmit or approve
  the file explicitly.
• A stale approval-card answer tells the model in the same turn that approval did not apply, plan mode is still on,
  and it must show the current plan and submit it again.
• Move previews keep the tails of both source and destination on Telegram, Slack and Discord's 250-character prompts (#46).
• Add the Approval card switch (approval_card, on by default): off uses Hermes' approval prompt, keeps the other
  lean settings, and wins over custom lever overrides. It takes effect at once, so change it between plans.