R8.1: document content keeps the file's colours in a dark app

Pages, cells, slides and PDF pages paint as the file says in any
appearance; only the chrome around them follows dark mode. The
kernel keeps Ely's one light scheme, sent once a view, and MuPDF
no longer inverts. Reviews now run gpt-6.1-sol at xhigh.

Co-Authored-By: Claude <noreply@anthropic.com>

scripts/review.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# Usage: review.sh <item-id> <round> [path...] — codex max, fast review.
+# Usage: review.sh <item-id> <round> [path...] — codex xhigh, fast review.
 set -euo pipefail
 
 [ "${HERDR_ENV:-}" = 1 ] || { echo "review.sh: not inside herdr" >&2; exit 2; }
@@ -37,7 +37,7 @@ pane=$(herdr pane split --current --direction right --cwd "$PWD" --no-focus | jq
 echo "$pane" >"$last"
 started=
 for _ in 1 2 3 4 5; do
-  if err=$(herdr agent start "$name" --kind codex --pane "$pane" --timeout 120000 -- --yolo --model gpt-6-astra -c 'model_reasoning_effort="max"' -c 'service_tier="fast"' -c check_for_update_on_startup=false 2>&1); then
+  if err=$(herdr agent start "$name" --kind codex --pane "$pane" --timeout 120000 -- --yolo --model gpt-6.1-sol -c 'model_reasoning_effort="xhigh"' -c 'service_tier="fast"' -c check_for_update_on_startup=false 2>&1); then
     started=1
     break
   fi