docs(invocation-mode): grade sync and tidy-work KEEP per the #6458 decision #9176

This was generated by AI during attend-queue.

Refs: #6458

Problem

The owner decided on #6458 (2026-10-22) that repo-fleet-hygiene:sync and session-flow:tidy-work stay human-started: with no person present their approval is skill text only. docs/conventions/invocation-mode/README.md:355-356 still grades both FLIP → false.

Done when

• The two rows grade KEEP (true), citing the 2026-10-22 decision on feat(context-budget): keep plugin skill descriptions visible when the skill listing overflows #6458 as their class reason.
• scripts/check-affected.sh --uncommitted passes.