Codex SHIP-ONLY-WITH-FIXES (3 real issues; Codex+Opus disagreed on #1, stricter wins):
1. CORE — .messages lost overflow-anchor:none, reopening the #1360 (d21c9720) streaming-scroll-anchor regression. Restored it (native anchoring stays OFF; the RO does the settle). Opus had judged this removal acceptable; took Codex's stricter call.
2. SILENT — the ResizeObserver observed #messages (the scroll container, fixed by flex layout, never resizes) instead of #msgInner (.messages-inner, the growing transcript node) → callback would never fire. Now observes #msgInner.
3. SILENT — stale RO callbacks mutated the global _settleRO, which could disconnect a newer active observer after settle re-entry. Now instance-owned: close over const ro, only clear the global when _settleRO===ro.
b5eabe1494
