docs(update arc): record the operator's rulings of 2026-09-23 (09 §3 decisions 11-18)

- 09 §3: decisions 11 (one window = a leg of the backup chain), 12 (automatic,
  per-box switch on by default), 13 (the test decides, not the tag - replaces
  decision 3's "never across a major"), 14 (the ladder), 15 (the box undoes a
  failed update - replaces §6.1's no-auto-undo), 16 (Postgres majors converted
  by the box), 17 (digests), 18 (fleet view, later).
- 09 §3b marked ANSWERED with a pointer per question; kept as the reasoning.
- 09 §6.2 rewritten to the ruled shape; §6.1 abort paragraph and §4 point at 15.
- Register: R-450, R-451, R-446, R-463 cite the decisions.
- STATUS: the seven questions no longer wait on the operator.

Documents only. No product code.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

STATUS.md

@@ -1,5 +1,9 @@
 # STATUS — what works, what's broken, what's next
 
+**Updated 2026-09-23 (morning) — your seven answers on automatic updates are written into the design notes as rulings.** No later session will ask them again. The two new pieces your answers need — the automatic undo and the step-by-step climb — are being tested by hand on the scratch machine today, before anyone builds them. The build plan comes back to you part by part.
+
+---
+
 **Updated 2026-09-22 (late) — I fixed the six faults the two drill nights found in the update, delete and hold machinery, and shipped the six app versions you approved. One thing needs your word: whether the fleet moves to the new controller.**
 
 **Decisions I took on my own: none.**