docs: D-57 and D-58, the owner's answers to Q-5 and Q-8

Q-5: one format upgrade of the live books, after S7 and P4 have landed,
declaring documents_v2 and drafts_v2 together (D-52 confirmed; A-14
records it). Q-8: the review's decisions D-47 to D-54 are the owner's;
the "may revisit" clauses are closed. Both asked and answered through
the question tool on 2026-10-28. The owner also chose to have the
planning session merge the paused branches itself.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

plan/STATUS.md

@@ -55,6 +55,10 @@ keyring and only the Linux Secret Service store exists, so on macOS
 CI. P11a gains step 0 for exactly that groundwork and starts now, beside
 the P4b finish; the P10 chain (P4, P5, P8) keeps its order.
 
+**Answered 2026-10-28 (the question tool):** Q-5, one format upgrade after
+S7 and P4 (D-57); Q-8, D-47 to D-54 stand (D-58); the planning session
+does the merges itself; the website is redeployed with the macOS wording.
+
 **Next, in order:** (1) resume the five branches in the 8.0.2 order,
 each rebased and `just check`ed again (the pause killed every gate),
 P6 last with its gate run to the end and its dependency reviewed; (2)