Tasks: Prompt submission preserves permission decisions

• Record the existing contract and clarified acceptance criteria.
• Reproduce delayed Enter reaching a new permission request with exact PTY bytes.
• Guard delayed Enter and retry against current decision state.
• Verify the regression and existing submission behaviors.
• Reproduce follow-up confirmation ignoring a pending decision.
• Preserve pending decisions in task resume and background ready.
• Reproduce and preserve recoverability for background refusal after paste.
• Document partial-delivery behavior and run full verification; record GTK gate failures.
• Complete independent review.
• Publish draft PR https://github.com/Lucenx9/signaltty/pull/38.